diff --git a/beacon-chain/blockchain/error.go b/beacon-chain/blockchain/error.go
index ae689fb8bb..cb6e20c4c9 100644
--- a/beacon-chain/blockchain/error.go
+++ b/beacon-chain/blockchain/error.go
@@ -17,8 +17,6 @@ var (
 	errNilJustifiedCheckpoint = errors.New("nil justified checkpoint returned from state")
 	// errBlockDoesNotExist is returned when a block does not exist for a particular state summary.
 	errBlockDoesNotExist = errors.New("could not find block in DB")
-	// errWrongBlockCount is returned when the wrong number of blocks or block roots is used
-	errWrongBlockCount = errors.New("wrong number of blocks or block roots")
 	// errBlockNotFoundInCacheOrDB is returned when a block is not found in the cache or DB.
 	errBlockNotFoundInCacheOrDB = errors.New("block not found in cache or db")
 	// errWSBlockNotFound is returned when a block is not found in the WS cache or DB.
diff --git a/beacon-chain/blockchain/log.go b/beacon-chain/blockchain/log.go
index f74019fd33..2c9b60e3e7 100644
--- a/beacon-chain/blockchain/log.go
+++ b/beacon-chain/blockchain/log.go
@@ -73,7 +73,7 @@ func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte
 	level := log.Logger.GetLevel()
 	if level >= logrus.DebugLevel {
 		parentRoot := block.ParentRoot()
-		log.WithFields(logrus.Fields{
+		lf := logrus.Fields{
 			"slot":                      block.Slot(),
 			"slotInEpoch":               block.Slot() % params.BeaconConfig().SlotsPerEpoch,
 			"block":                     fmt.Sprintf("0x%s...", hex.EncodeToString(blockRoot[:])[:8]),
@@ -87,7 +87,12 @@ func logBlockSyncStatus(block interfaces.ReadOnlyBeaconBlock, blockRoot [32]byte
 			"sinceSlotStartTime":        prysmTime.Now().Sub(startTime),
 			"chainServiceProcessedTime": prysmTime.Now().Sub(receivedTime),
 			"deposits":                  len(block.Body().Deposits()),
-		}).Debug("Synced new block")
+		}
+		commits, err := block.Body().BlobKzgCommitments()
+		if err == nil {
+			lf["commitments"] = len(commits)
+		}
+		log.WithFields(lf).Debug("Synced new block")
 	} else {
 		log.WithFields(logrus.Fields{
 			"slot":           block.Slot(),
diff --git a/beacon-chain/blockchain/process_block.go b/beacon-chain/blockchain/process_block.go
index b5da2308d8..1290e73905 100644
--- a/beacon-chain/blockchain/process_block.go
+++ b/beacon-chain/blockchain/process_block.go
@@ -160,19 +160,14 @@ func getStateVersionAndPayload(st state.BeaconState) (int, interfaces.ExecutionD
 	return preStateVersion, preStateHeader, nil
 }
 
-func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock,
-	blockRoots [][32]byte) error {
+func (s *Service) onBlockBatch(ctx context.Context, blks []consensusblocks.ROBlock) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.onBlockBatch")
 	defer span.End()
 
-	if len(blks) == 0 || len(blockRoots) == 0 {
+	if len(blks) == 0 {
 		return errors.New("no blocks provided")
 	}
 
-	if len(blks) != len(blockRoots) {
-		return errWrongBlockCount
-	}
-
 	if err := consensusblocks.BeaconBlockIsNil(blks[0]); err != nil {
 		return invalidBlock{error: err}
 	}
@@ -222,7 +217,7 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 		}
 		// Save potential boundary states.
 		if slots.IsEpochStart(preState.Slot()) {
-			boundaries[blockRoots[i]] = preState.Copy()
+			boundaries[b.Root()] = preState.Copy()
 		}
 		jCheckpoints[i] = preState.CurrentJustifiedCheckpoint()
 		fCheckpoints[i] = preState.FinalizedCheckpoint()
@@ -255,11 +250,12 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 	pendingNodes := make([]*forkchoicetypes.BlockAndCheckpoints, len(blks))
 	var isValidPayload bool
 	for i, b := range blks {
+		root := b.Root()
 		isValidPayload, err = s.notifyNewPayload(ctx,
 			postVersionAndHeaders[i].version,
 			postVersionAndHeaders[i].header, b)
 		if err != nil {
-			return s.handleInvalidExecutionError(ctx, err, blockRoots[i], b.Block().ParentRoot())
+			return s.handleInvalidExecutionError(ctx, err, root, b.Block().ParentRoot())
 		}
 		if isValidPayload {
 			if err := s.validateMergeTransitionBlock(ctx, preVersionAndHeaders[i].version,
@@ -271,13 +267,13 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 			JustifiedCheckpoint: jCheckpoints[i],
 			FinalizedCheckpoint: fCheckpoints[i]}
 		pendingNodes[len(blks)-i-1] = args
-		if err := s.saveInitSyncBlock(ctx, blockRoots[i], b); err != nil {
+		if err := s.saveInitSyncBlock(ctx, root, b); err != nil {
 			tracing.AnnotateError(span, err)
 			return err
 		}
 		if err := s.cfg.BeaconDB.SaveStateSummary(ctx, &ethpb.StateSummary{
 			Slot: b.Block().Slot(),
-			Root: blockRoots[i][:],
+			Root: root[:],
 		}); err != nil {
 			tracing.AnnotateError(span, err)
 			return err
@@ -301,8 +297,9 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 			return err
 		}
 	}
+	lastB := blks[len(blks)-1]
+	lastBR := lastB.Root()
 	// Also saves the last post state which to be used as pre state for the next batch.
-	lastBR := blockRoots[len(blks)-1]
 	if err := s.cfg.StateGen.SaveState(ctx, lastBR, preState); err != nil {
 		return err
 	}
@@ -320,7 +317,6 @@ func (s *Service) onBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySi
 			return errors.Wrap(err, "could not set optimistic block to valid")
 		}
 	}
-	lastB := blks[len(blks)-1]
 	arg := &notifyForkchoiceUpdateArg{
 		headState: preState,
 		headRoot:  lastBR,
diff --git a/beacon-chain/blockchain/process_block_test.go b/beacon-chain/blockchain/process_block_test.go
index ac83ecb1cc..824d965306 100644
--- a/beacon-chain/blockchain/process_block_test.go
+++ b/beacon-chain/blockchain/process_block_test.go
@@ -49,8 +49,7 @@ func TestStore_OnBlockBatch(t *testing.T) {
 	require.NoError(t, service.saveGenesisData(ctx, st))
 	bState := st.Copy()
 
-	var blks []interfaces.ReadOnlySignedBeaconBlock
-	var blkRoots [][32]byte
+	var blks []consensusblocks.ROBlock
 	for i := 0; i < 97; i++ {
 		b, err := util.GenerateFullBlock(bState, keys, util.DefaultBlockGenConfig(), primitives.Slot(i))
 		require.NoError(t, err)
@@ -63,16 +62,15 @@ func TestStore_OnBlockBatch(t *testing.T) {
 		require.NoError(t, service.saveInitSyncBlock(ctx, root, wsb))
 		wsb, err = consensusblocks.NewSignedBeaconBlock(b)
 		require.NoError(t, err)
-		blks = append(blks, wsb)
-		blkRoots = append(blkRoots, root)
+		rwsb, err := consensusblocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		blks = append(blks, rwsb)
 	}
-	err := service.onBlockBatch(ctx, blks, blkRoots[1:])
-	require.ErrorIs(t, errWrongBlockCount, err)
-	err = service.onBlockBatch(ctx, blks, blkRoots)
+	err := service.onBlockBatch(ctx, blks)
 	require.NoError(t, err)
 	jcp := service.CurrentJustifiedCheckpt()
 	jroot := bytesutil.ToBytes32(jcp.Root)
-	require.Equal(t, blkRoots[63], jroot)
+	require.Equal(t, blks[63].Root(), jroot)
 	require.Equal(t, primitives.Epoch(2), service.cfg.ForkChoiceStore.JustifiedCheckpoint().Epoch)
 }
 
@@ -84,8 +82,7 @@ func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
 	require.NoError(t, service.saveGenesisData(ctx, st))
 	bState := st.Copy()
 
-	var blks []interfaces.ReadOnlySignedBeaconBlock
-	var blkRoots [][32]byte
+	var blks []consensusblocks.ROBlock
 	blkCount := 4
 	for i := 0; i <= blkCount; i++ {
 		b, err := util.GenerateFullBlock(bState, keys, util.DefaultBlockGenConfig(), primitives.Slot(i))
@@ -94,13 +91,12 @@ func TestStore_OnBlockBatch_NotifyNewPayload(t *testing.T) {
 		require.NoError(t, err)
 		bState, err = transition.ExecuteStateTransition(ctx, bState, wsb)
 		require.NoError(t, err)
-		root, err := b.Block.HashTreeRoot()
+		rwsb, err := consensusblocks.NewROBlock(wsb)
 		require.NoError(t, err)
-		require.NoError(t, service.saveInitSyncBlock(ctx, root, wsb))
-		blks = append(blks, wsb)
-		blkRoots = append(blkRoots, root)
+		require.NoError(t, service.saveInitSyncBlock(ctx, rwsb.Root(), wsb))
+		blks = append(blks, rwsb)
 	}
-	require.NoError(t, service.onBlockBatch(ctx, blks, blkRoots))
+	require.NoError(t, service.onBlockBatch(ctx, blks))
 }
 
 func TestCachedPreState_CanGetFromStateSummary(t *testing.T) {
@@ -1932,8 +1928,10 @@ func TestNoViableHead_Reboot(t *testing.T) {
 	require.NoError(t, err)
 	root, err = b.Block.HashTreeRoot()
 	require.NoError(t, err)
+	rwsb, err := consensusblocks.NewROBlock(wsb)
+	require.NoError(t, err)
 	// We use onBlockBatch here because the valid chain is missing in forkchoice
-	require.NoError(t, service.onBlockBatch(ctx, []interfaces.ReadOnlySignedBeaconBlock{wsb}, [][32]byte{root}))
+	require.NoError(t, service.onBlockBatch(ctx, []consensusblocks.ROBlock{rwsb}))
 	// Check that the head is now VALID and the node is not optimistic
 	require.Equal(t, genesisRoot, service.ensureRootNotZeros(service.cfg.ForkChoiceStore.CachedHeadRoot()))
 	headRoot, err = service.HeadRoot(ctx)
diff --git a/beacon-chain/blockchain/receive_block.go b/beacon-chain/blockchain/receive_block.go
index 40fbfd26e1..9265a121e0 100644
--- a/beacon-chain/blockchain/receive_block.go
+++ b/beacon-chain/blockchain/receive_block.go
@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/state"
 	"github.com/prysmaticlabs/prysm/v4/config/features"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
@@ -32,7 +33,7 @@ var epochsSinceFinalitySaveHotStateDB = primitives.Epoch(100)
 // BlockReceiver interface defines the methods of chain service for receiving and processing new blocks.
 type BlockReceiver interface {
 	ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error
-	ReceiveBlockBatch(ctx context.Context, blocks []interfaces.ReadOnlySignedBeaconBlock, blkRoots [][32]byte) error
+	ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error
 	HasBlock(ctx context.Context, root [32]byte) bool
 	RecentBlockSlot(root [32]byte) (primitives.Slot, error)
 }
@@ -172,7 +173,7 @@ func (s *Service) ReceiveBlock(ctx context.Context, block interfaces.ReadOnlySig
 // ReceiveBlockBatch processes the whole block batch at once, assuming the block batch is linear ,transitioning
 // the state, performing batch verification of all collected signatures and then performing the appropriate
 // actions for a block post-transition.
-func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.ReadOnlySignedBeaconBlock, blkRoots [][32]byte) error {
+func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []blocks.ROBlock) error {
 	ctx, span := trace.StartSpan(ctx, "blockChain.ReceiveBlockBatch")
 	defer span.End()
 
@@ -180,20 +181,21 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.Rea
 	defer s.cfg.ForkChoiceStore.Unlock()
 
 	// Apply state transition on the incoming newly received block batches, one by one.
-	if err := s.onBlockBatch(ctx, blocks, blkRoots); err != nil {
+	if err := s.onBlockBatch(ctx, blocks); err != nil {
 		err := errors.Wrap(err, "could not process block in batch")
 		tracing.AnnotateError(span, err)
 		return err
 	}
 
-	lastBR := blkRoots[len(blkRoots)-1]
+	lastBR := blocks[len(blocks)-1].Root()
 	optimistic, err := s.cfg.ForkChoiceStore.IsOptimistic(lastBR)
 	if err != nil {
 		lastSlot := blocks[len(blocks)-1].Block().Slot()
 		log.WithError(err).Errorf("Could not check if block is optimistic, Root: %#x, Slot: %d", lastBR, lastSlot)
 		optimistic = true
 	}
-	for i, b := range blocks {
+
+	for _, b := range blocks {
 		blockCopy, err := b.Copy()
 		if err != nil {
 			return err
@@ -203,7 +205,7 @@ func (s *Service) ReceiveBlockBatch(ctx context.Context, blocks []interfaces.Rea
 			Type: statefeed.BlockProcessed,
 			Data: &statefeed.BlockProcessedData{
 				Slot:        blockCopy.Block().Slot(),
-				BlockRoot:   blkRoots[i],
+				BlockRoot:   b.Root(),
 				SignedBlock: blockCopy,
 				Verified:    true,
 				Optimistic:  optimistic,
diff --git a/beacon-chain/blockchain/receive_block_test.go b/beacon-chain/blockchain/receive_block_test.go
index 39f4e9301a..19bd3e78c0 100644
--- a/beacon-chain/blockchain/receive_block_test.go
+++ b/beacon-chain/blockchain/receive_block_test.go
@@ -10,7 +10,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/operations/voluntaryexits"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
@@ -228,13 +227,11 @@ func TestService_ReceiveBlockBatch(t *testing.T) {
 			s, _ := minimalTestService(t, WithStateNotifier(&blockchainTesting.MockStateNotifier{RecordEvents: true}))
 			err := s.saveGenesisData(ctx, genesis)
 			require.NoError(t, err)
-			root, err := tt.args.block.Block.HashTreeRoot()
-			require.NoError(t, err)
 			wsb, err := blocks.NewSignedBeaconBlock(tt.args.block)
 			require.NoError(t, err)
-			blks := []interfaces.ReadOnlySignedBeaconBlock{wsb}
-			roots := [][32]byte{root}
-			err = s.ReceiveBlockBatch(ctx, blks, roots)
+			rwsb, err := blocks.NewROBlock(wsb)
+			require.NoError(t, err)
+			err = s.ReceiveBlockBatch(ctx, []blocks.ROBlock{rwsb})
 			if tt.wantedErr != "" {
 				assert.ErrorContains(t, tt.wantedErr, err)
 			} else {
diff --git a/beacon-chain/blockchain/testing/BUILD.bazel b/beacon-chain/blockchain/testing/BUILD.bazel
index 7c76446f0c..4a80b90820 100644
--- a/beacon-chain/blockchain/testing/BUILD.bazel
+++ b/beacon-chain/blockchain/testing/BUILD.bazel
@@ -23,6 +23,7 @@ go_library(
         "//beacon-chain/state/state-native:go_default_library",
         "//config/fieldparams:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
diff --git a/beacon-chain/blockchain/testing/mock.go b/beacon-chain/blockchain/testing/mock.go
index 8c6fbd6f67..a6d5f2abf1 100644
--- a/beacon-chain/blockchain/testing/mock.go
+++ b/beacon-chain/blockchain/testing/mock.go
@@ -22,6 +22,7 @@ import (
 	state_native "github.com/prysmaticlabs/prysm/v4/beacon-chain/state/state-native"
 	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
@@ -204,7 +205,7 @@ func (s *ChainService) ReceiveBlockInitialSync(ctx context.Context, block interf
 }
 
 // ReceiveBlockBatch processes blocks in batches from initial-sync.
-func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock, _ [][32]byte) error {
+func (s *ChainService) ReceiveBlockBatch(ctx context.Context, blks []blocks.ROBlock) error {
 	if s.State == nil {
 		return ErrNilState
 	}
diff --git a/beacon-chain/execution/BUILD.bazel b/beacon-chain/execution/BUILD.bazel
index e91895898d..68f4d5d9a7 100644
--- a/beacon-chain/execution/BUILD.bazel
+++ b/beacon-chain/execution/BUILD.bazel
@@ -71,6 +71,7 @@ go_library(
         "@com_github_sirupsen_logrus//:go_default_library",
         "@io_k8s_client_go//tools/cache:go_default_library",
         "@io_opencensus_go//trace:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )
 
diff --git a/beacon-chain/execution/engine_client.go b/beacon-chain/execution/engine_client.go
index 3e9c607ed2..4e98c9da29 100644
--- a/beacon-chain/execution/engine_client.go
+++ b/beacon-chain/execution/engine_client.go
@@ -28,6 +28,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
+	"google.golang.org/protobuf/proto"
 )
 
 var (
@@ -582,7 +583,10 @@ func (s *Service) ReconstructFullBlock(
 	// If the payload header has a block hash of 0x0, it means we are pre-merge and should
 	// simply return the block with an empty execution payload.
 	if bytes.Equal(header.BlockHash(), params.BeaconConfig().ZeroHash[:]) {
-		payload := buildEmptyExecutionPayload()
+		payload, err := buildEmptyExecutionPayload(blindedBlock.Version())
+		if err != nil {
+			return nil, err
+		}
 		return blocks.BuildSignedBeaconBlockFromExecutionPayload(blindedBlock, payload)
 	}
 
@@ -641,7 +645,11 @@ func (s *Service) ReconstructFullBellatrixBlockBatch(
 	// For blocks that are pre-merge we simply reconstruct them via an empty
 	// execution payload.
 	for _, realIdx := range zeroExecPayloads {
-		payload := buildEmptyExecutionPayload()
+		bblock := blindedBlocks[realIdx]
+		payload, err := buildEmptyExecutionPayload(bblock.Version())
+		if err != nil {
+			return nil, err
+		}
 		fullBlock, err := blocks.BuildSignedBeaconBlockFromExecutionPayload(blindedBlocks[realIdx], payload)
 		if err != nil {
 			return nil, err
@@ -677,7 +685,7 @@ func (s *Service) retrievePayloadFromExecutionHash(ctx context.Context, executio
 	}
 
 	executionBlock.Version = version
-	return fullPayloadFromExecutionBlock(header, executionBlock)
+	return fullPayloadFromExecutionBlock(version, header, executionBlock)
 }
 
 func (s *Service) retrievePayloadsFromExecutionHashes(
@@ -705,6 +713,7 @@ func (s *Service) retrievePayloadsFromExecutionHashes(
 	// blinded block.
 	for sliceIdx, realIdx := range validExecPayloads {
 		var payload interfaces.ExecutionData
+		bblock := blindedBlocks[realIdx]
 		if features.Get().EnableOptionalEngineMethods {
 			b := payloadBodies[sliceIdx]
 			if b == nil {
@@ -727,7 +736,7 @@ func (s *Service) retrievePayloadsFromExecutionHashes(
 			if err != nil {
 				return nil, err
 			}
-			payload, err = fullPayloadFromExecutionBlock(header, b)
+			payload, err = fullPayloadFromExecutionBlock(bblock.Version(), header, b)
 			if err != nil {
 				return nil, err
 			}
@@ -742,7 +751,7 @@ func (s *Service) retrievePayloadsFromExecutionHashes(
 }
 
 func fullPayloadFromExecutionBlock(
-	header interfaces.ExecutionData, block *pb.ExecutionBlock,
+	blockVersion int, header interfaces.ExecutionData, block *pb.ExecutionBlock,
 ) (interfaces.ExecutionData, error) {
 	if header.IsNil() || block == nil {
 		return nil, errors.New("execution block and header cannot be nil")
@@ -765,7 +774,7 @@ func fullPayloadFromExecutionBlock(
 		txs[i] = txBin
 	}
 
-	switch block.Version {
+	switch blockVersion {
 	case version.Bellatrix:
 		return blocks.WrappedExecutionPayload(&pb.ExecutionPayload{
 			ParentHash:    header.ParentHash(),
@@ -997,18 +1006,51 @@ func tDStringToUint256(td string) (*uint256.Int, error) {
 	return i, nil
 }
 
-func buildEmptyExecutionPayload() *pb.ExecutionPayload {
-	return &pb.ExecutionPayload{
-		ParentHash:    make([]byte, fieldparams.RootLength),
-		FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
-		StateRoot:     make([]byte, fieldparams.RootLength),
-		ReceiptsRoot:  make([]byte, fieldparams.RootLength),
-		LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
-		PrevRandao:    make([]byte, fieldparams.RootLength),
-		BaseFeePerGas: make([]byte, fieldparams.RootLength),
-		BlockHash:     make([]byte, fieldparams.RootLength),
-		Transactions:  make([][]byte, 0),
-		ExtraData:     make([]byte, 0),
+func buildEmptyExecutionPayload(v int) (proto.Message, error) {
+	switch v {
+	case version.Bellatrix:
+		return &pb.ExecutionPayload{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+		}, nil
+	case version.Capella:
+		return &pb.ExecutionPayloadCapella{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+			Withdrawals:   make([]*pb.Withdrawal, 0),
+		}, nil
+	case version.Deneb:
+		return &pb.ExecutionPayloadDeneb{
+			ParentHash:    make([]byte, fieldparams.RootLength),
+			FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+			StateRoot:     make([]byte, fieldparams.RootLength),
+			ReceiptsRoot:  make([]byte, fieldparams.RootLength),
+			LogsBloom:     make([]byte, fieldparams.LogsBloomLength),
+			PrevRandao:    make([]byte, fieldparams.RootLength),
+			BaseFeePerGas: make([]byte, fieldparams.RootLength),
+			BlockHash:     make([]byte, fieldparams.RootLength),
+			Transactions:  make([][]byte, 0),
+			ExtraData:     make([]byte, 0),
+			Withdrawals:   make([]*pb.Withdrawal, 0),
+		}, nil
+	default:
+		return nil, errors.Wrapf(ErrUnsupportedVersion, "version=%s", version.String(v))
 	}
 }
 
diff --git a/beacon-chain/execution/engine_client_test.go b/beacon-chain/execution/engine_client_test.go
index c971888004..06af6b3f35 100644
--- a/beacon-chain/execution/engine_client_test.go
+++ b/beacon-chain/execution/engine_client_test.go
@@ -1604,8 +1604,9 @@ func fixtures() map[string]interface{} {
 
 func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 	type args struct {
-		header *pb.ExecutionPayloadHeader
-		block  *pb.ExecutionBlock
+		header  *pb.ExecutionPayloadHeader
+		block   *pb.ExecutionBlock
+		version int
 	}
 	wantedHash := common.BytesToHash([]byte("foo"))
 	tests := []struct {
@@ -1621,9 +1622,9 @@ func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 					BlockHash: []byte("foo"),
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Bellatrix,
-					Hash:    common.BytesToHash([]byte("bar")),
+					Hash: common.BytesToHash([]byte("bar")),
 				},
+				version: version.Bellatrix,
 			},
 			err: "does not match execution block hash",
 		},
@@ -1634,9 +1635,9 @@ func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 					BlockHash: wantedHash[:],
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Bellatrix,
-					Hash:    wantedHash,
+					Hash: wantedHash,
 				},
+				version: version.Bellatrix,
 			},
 			want: func() interfaces.ExecutionData {
 				p, err := blocks.WrappedExecutionPayload(&pb.ExecutionPayload{
@@ -1652,7 +1653,7 @@ func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			wrapped, err := blocks.WrappedExecutionPayloadHeader(tt.args.header)
 			require.NoError(t, err)
-			got, err := fullPayloadFromExecutionBlock(wrapped, tt.args.block)
+			got, err := fullPayloadFromExecutionBlock(tt.args.version, wrapped, tt.args.block)
 			if err != nil {
 				assert.ErrorContains(t, tt.err, err)
 			} else {
@@ -1664,8 +1665,9 @@ func Test_fullPayloadFromExecutionBlock(t *testing.T) {
 
 func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
 	type args struct {
-		header *pb.ExecutionPayloadHeaderCapella
-		block  *pb.ExecutionBlock
+		header  *pb.ExecutionPayloadHeaderCapella
+		block   *pb.ExecutionBlock
+		version int
 	}
 	wantedHash := common.BytesToHash([]byte("foo"))
 	tests := []struct {
@@ -1681,9 +1683,9 @@ func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
 					BlockHash: []byte("foo"),
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Capella,
-					Hash:    common.BytesToHash([]byte("bar")),
+					Hash: common.BytesToHash([]byte("bar")),
 				},
+				version: version.Capella,
 			},
 			err: "does not match execution block hash",
 		},
@@ -1694,9 +1696,9 @@ func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
 					BlockHash: wantedHash[:],
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Capella,
-					Hash:    wantedHash,
+					Hash: wantedHash,
 				},
+				version: version.Capella,
 			},
 			want: func() interfaces.ExecutionData {
 				p, err := blocks.WrappedExecutionPayloadCapella(&pb.ExecutionPayloadCapella{
@@ -1712,7 +1714,7 @@ func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			wrapped, err := blocks.WrappedExecutionPayloadHeaderCapella(tt.args.header, 0)
 			require.NoError(t, err)
-			got, err := fullPayloadFromExecutionBlock(wrapped, tt.args.block)
+			got, err := fullPayloadFromExecutionBlock(tt.args.version, wrapped, tt.args.block)
 			if err != nil {
 				assert.ErrorContains(t, tt.err, err)
 			} else {
@@ -1724,8 +1726,9 @@ func Test_fullPayloadFromExecutionBlockCapella(t *testing.T) {
 
 func Test_fullPayloadFromExecutionBlockDeneb(t *testing.T) {
 	type args struct {
-		header *pb.ExecutionPayloadHeaderDeneb
-		block  *pb.ExecutionBlock
+		header  *pb.ExecutionPayloadHeaderDeneb
+		block   *pb.ExecutionBlock
+		version int
 	}
 	wantedHash := common.BytesToHash([]byte("foo"))
 	tests := []struct {
@@ -1741,9 +1744,9 @@ func Test_fullPayloadFromExecutionBlockDeneb(t *testing.T) {
 					BlockHash: []byte("foo"),
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Deneb,
-					Hash:    common.BytesToHash([]byte("bar")),
+					Hash: common.BytesToHash([]byte("bar")),
 				},
+				version: version.Deneb,
 			},
 			err: "does not match execution block hash",
 		},
@@ -1754,9 +1757,9 @@ func Test_fullPayloadFromExecutionBlockDeneb(t *testing.T) {
 					BlockHash: wantedHash[:],
 				},
 				block: &pb.ExecutionBlock{
-					Version: version.Deneb,
-					Hash:    wantedHash,
+					Hash: wantedHash,
 				},
+				version: version.Deneb,
 			},
 			want: func() interfaces.ExecutionData {
 				p, err := blocks.WrappedExecutionPayloadDeneb(&pb.ExecutionPayloadDeneb{
@@ -1772,7 +1775,7 @@ func Test_fullPayloadFromExecutionBlockDeneb(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			wrapped, err := blocks.WrappedExecutionPayloadHeaderDeneb(tt.args.header, 0)
 			require.NoError(t, err)
-			got, err := fullPayloadFromExecutionBlock(wrapped, tt.args.block)
+			got, err := fullPayloadFromExecutionBlock(tt.args.version, wrapped, tt.args.block)
 			if err != nil {
 				assert.ErrorContains(t, tt.err, err)
 			} else {
diff --git a/beacon-chain/execution/errors.go b/beacon-chain/execution/errors.go
index c27329c101..d6197c986a 100644
--- a/beacon-chain/execution/errors.go
+++ b/beacon-chain/execution/errors.go
@@ -36,4 +36,6 @@ var (
 	ErrNilResponse = errors.New("nil response")
 	// ErrRequestTooLarge when the request is too large
 	ErrRequestTooLarge = errors.New("request too large")
+	// ErrUnsupportedVersion represents a case where a payload is requested for a block type that doesn't have a known mapping.
+	ErrUnsupportedVersion = errors.New("unknown ExecutionPayload schema for block version")
 )
diff --git a/beacon-chain/sync/initial-sync/BUILD.bazel b/beacon-chain/sync/initial-sync/BUILD.bazel
index bbb7929e09..ba321bad4f 100644
--- a/beacon-chain/sync/initial-sync/BUILD.bazel
+++ b/beacon-chain/sync/initial-sync/BUILD.bazel
@@ -29,10 +29,13 @@ go_library(
         "//beacon-chain/sync:go_default_library",
         "//cmd/beacon-chain/flags:go_default_library",
         "//config/params:go_default_library",
+        "//consensus-types:go_default_library",
+        "//consensus-types/blocks:go_default_library",
         "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//container/leaky-bucket:go_default_library",
         "//crypto/rand:go_default_library",
+        "//encoding/bytesutil:go_default_library",
         "//math:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
         "//runtime:go_default_library",
@@ -50,6 +53,7 @@ go_test(
     name = "go_raceon_test",
     srcs = [
         "blocks_fetcher_test.go",
+        "blocks_fetcher_utils_test.go",
         "blocks_queue_test.go",
         "fsm_test.go",
         "initial_sync_test.go",
diff --git a/beacon-chain/sync/initial-sync/blocks_fetcher.go b/beacon-chain/sync/initial-sync/blocks_fetcher.go
index 6b1297c523..0a9bdb45c8 100644
--- a/beacon-chain/sync/initial-sync/blocks_fetcher.go
+++ b/beacon-chain/sync/initial-sync/blocks_fetcher.go
@@ -3,6 +3,8 @@ package initialsync
 import (
 	"context"
 	"fmt"
+	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -11,15 +13,20 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
 	p2pTypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
 	prysmsync "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
+	consensus_types "github.com/prysmaticlabs/prysm/v4/consensus-types"
+	blocks2 "github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	leakybucket "github.com/prysmaticlabs/prysm/v4/container/leaky-bucket"
 	"github.com/prysmaticlabs/prysm/v4/crypto/rand"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	"github.com/prysmaticlabs/prysm/v4/math"
 	p2ppb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
 	"go.opencensus.io/trace"
 )
@@ -60,6 +67,8 @@ var blockLimiterPeriod = 30 * time.Second
 
 // blocksFetcherConfig is a config to setup the block fetcher.
 type blocksFetcherConfig struct {
+	clock                    *startup.Clock
+	ctxMap                   prysmsync.ContextByteVersions
 	chain                    blockchainService
 	p2p                      p2p.P2P
 	db                       db.ReadOnlyDatabase
@@ -76,6 +85,8 @@ type blocksFetcher struct {
 	cancel          context.CancelFunc
 	rand            *rand.Rand
 	chain           blockchainService
+	clock           *startup.Clock
+	ctxMap          prysmsync.ContextByteVersions
 	p2p             p2p.P2P
 	db              db.ReadOnlyDatabase
 	blocksPerPeriod uint64
@@ -104,11 +115,11 @@ type fetchRequestParams struct {
 // fetchRequestResponse is a combined type to hold results of both successful executions and errors.
 // Valid usage pattern will be to check whether result's `err` is nil, before using `blocks`.
 type fetchRequestResponse struct {
-	pid    peer.ID
-	start  primitives.Slot
-	count  uint64
-	blocks []interfaces.ReadOnlySignedBeaconBlock
-	err    error
+	pid   peer.ID
+	start primitives.Slot
+	count uint64
+	bwb   []blocks2.BlockWithVerifiedBlobs
+	err   error
 }
 
 // newBlocksFetcher creates ready to use fetcher.
@@ -131,6 +142,8 @@ func newBlocksFetcher(ctx context.Context, cfg *blocksFetcherConfig) *blocksFetc
 		cancel:          cancel,
 		rand:            rand.NewGenerator(),
 		chain:           cfg.chain,
+		clock:           cfg.clock,
+		ctxMap:          cfg.ctxMap,
 		p2p:             cfg.p2p,
 		db:              cfg.db,
 		blocksPerPeriod: uint64(blocksPerPeriod),
@@ -246,10 +259,10 @@ func (f *blocksFetcher) handleRequest(ctx context.Context, start primitives.Slot
 	defer span.End()
 
 	response := &fetchRequestResponse{
-		start:  start,
-		count:  count,
-		blocks: []interfaces.ReadOnlySignedBeaconBlock{},
-		err:    nil,
+		start: start,
+		count: count,
+		bwb:   []blocks2.BlockWithVerifiedBlobs{},
+		err:   nil,
 	}
 
 	if ctx.Err() != nil {
@@ -273,7 +286,14 @@ func (f *blocksFetcher) handleRequest(ctx context.Context, start primitives.Slot
 		}
 	}
 
-	response.blocks, response.pid, response.err = f.fetchBlocksFromPeer(ctx, start, count, peers)
+	response.bwb, response.pid, response.err = f.fetchBlocksFromPeer(ctx, start, count, peers)
+	if response.err == nil {
+		bwb, err := f.fetchBlobsFromPeer(ctx, response.bwb, response.pid)
+		if err != nil {
+			response.err = err
+		}
+		response.bwb = bwb
+	}
 	return response
 }
 
@@ -282,7 +302,7 @@ func (f *blocksFetcher) fetchBlocksFromPeer(
 	ctx context.Context,
 	start primitives.Slot, count uint64,
 	peers []peer.ID,
-) ([]interfaces.ReadOnlySignedBeaconBlock, peer.ID, error) {
+) ([]blocks2.BlockWithVerifiedBlobs, peer.ID, error) {
 	ctx, span := trace.StartSpan(ctx, "initialsync.fetchBlocksFromPeer")
 	defer span.End()
 
@@ -293,17 +313,183 @@ func (f *blocksFetcher) fetchBlocksFromPeer(
 		Step:      1,
 	}
 	for i := 0; i < len(peers); i++ {
-		blocks, err := f.requestBlocks(ctx, req, peers[i])
-		if err == nil {
-			f.p2p.Peers().Scorers().BlockProviderScorer().Touch(peers[i])
-			return blocks, peers[i], nil
-		} else {
-			log.WithError(err).Debug("Could not request blocks by range")
+		p := peers[i]
+		blocks, err := f.requestBlocks(ctx, req, p)
+		if err != nil {
+			log.WithField("peer", p).WithError(err).Debug("Could not request blocks by range from peer")
+			continue
 		}
+		f.p2p.Peers().Scorers().BlockProviderScorer().Touch(p)
+		robs, err := sortedBlockWithVerifiedBlobSlice(blocks)
+		if err != nil {
+			log.WithField("peer", p).WithError(err).Debug("invalid BeaconBlocksByRange response")
+			continue
+		}
+		return robs, p, err
 	}
 	return nil, "", errNoPeersAvailable
 }
 
+func sortedBlockWithVerifiedBlobSlice(blocks []interfaces.ReadOnlySignedBeaconBlock) ([]blocks2.BlockWithVerifiedBlobs, error) {
+	rb := make([]blocks2.BlockWithVerifiedBlobs, len(blocks))
+	for i, b := range blocks {
+		ro, err := blocks2.NewROBlock(b)
+		if err != nil {
+			return nil, err
+		}
+		rb[i] = blocks2.BlockWithVerifiedBlobs{Block: ro}
+	}
+	sort.Sort(blocks2.BlockWithVerifiedBlobsSlice(rb))
+	return rb, nil
+}
+
+func blobRequest(bwb []blocks2.BlockWithVerifiedBlobs, blobWindowStart primitives.Slot) *p2ppb.BlobSidecarsByRangeRequest {
+	if len(bwb) == 0 {
+		return nil
+	}
+	// Short-circuit if the highest block is before the deneb start epoch or retention period start.
+	// This assumes blocks are sorted by sortedBlockWithVerifiedBlobSlice.
+	highest := bwb[len(bwb)-1].Block.Block().Slot()
+	// bwb is sorted by slot, so if the last element is outside the retention window, no blobs are needed.
+	if highest < blobWindowStart {
+		return nil
+	}
+	lowest := lowestSlotNeedsBlob(blobWindowStart, bwb)
+	if lowest == nil {
+		return nil
+	}
+	return &p2ppb.BlobSidecarsByRangeRequest{
+		StartSlot: *lowest,
+		Count:     uint64(highest.SubSlot(*lowest)) + 1,
+	}
+}
+
+func lowestSlotNeedsBlob(retentionStart primitives.Slot, bwb []blocks2.BlockWithVerifiedBlobs) *primitives.Slot {
+	i := sort.Search(len(bwb), func(i int) bool {
+		if bwb[i].Block.Block().Slot() < retentionStart {
+			return false
+		}
+		commits, err := bwb[i].Block.Block().Body().BlobKzgCommitments()
+		if err != nil || len(commits) == 0 {
+			return false
+		}
+		return true
+	})
+	if i >= len(bwb) {
+		return nil
+	}
+	s := bwb[i].Block.Block().Slot()
+	return &s
+}
+
+func sortBlobs(blobs []*p2ppb.BlobSidecar) []*p2ppb.BlobSidecar {
+	sort.Slice(blobs, func(i, j int) bool {
+		if blobs[i].Slot == blobs[j].Slot {
+			return blobs[i].Index < blobs[j].Index
+		}
+		return blobs[i].Slot < blobs[j].Slot
+	})
+
+	return blobs
+}
+
+var errBlobVerification = errors.New("peer unable to serve aligned BlobSidecarsByRange and BeaconBlockSidecarsByRange responses")
+var errMissingBlobsForBlockCommitments = errors.Wrap(errBlobVerification, "blobs unavailable for processing block with kzg commitments")
+var errMismatchedBlobBlockRoot = errors.Wrap(errBlobVerification, "BlockRoot in BlobSidecar does not match the expected root")
+var errMissingBlobIndex = errors.Wrap(errBlobVerification, "missing expected blob index")
+var errMismatchedBlobCommitments = errors.Wrap(errBlobVerification, "commitments at given slot, root and index do not match")
+
+func verifyAndPopulateBlobs(bwb []blocks2.BlockWithVerifiedBlobs, blobs []*p2ppb.BlobSidecar, blobWindowStart primitives.Slot) ([]blocks2.BlockWithVerifiedBlobs, error) {
+	// Assumes bwb has already been sorted by sortedBlockWithVerifiedBlobSlice.
+	blobs = sortBlobs(blobs)
+	blobi := 0
+	// Loop over all blocks, and each time a commitment is observed, advance the index into the blob slice.
+	// The assumption is that the blob slice contains a value for every commitment in the blocks it is based on,
+	// correctly ordered by slot and blob index.
+	for i, bb := range bwb {
+		block := bb.Block.Block()
+		if block.Slot() < blobWindowStart {
+			continue
+		}
+		commits, err := block.Body().BlobKzgCommitments()
+		if err != nil {
+			if errors.Is(err, consensus_types.ErrUnsupportedField) {
+				log.
+					WithField("block_slot", block.Slot()).
+					WithField("retention_start", blobWindowStart).
+					Warn("block with slot within blob retention period has version which does not support commitments")
+				continue
+			}
+			return nil, err
+		}
+		bb.Blobs = make([]*p2ppb.BlobSidecar, len(commits))
+		for ci := range commits {
+			// There are more expected commitments in this block, but we've run out of blobs from the response
+			// (out-of-bound error guard).
+			if blobi == len(blobs) {
+				return nil, missingCommitError(bb.Block.Root(), commits[ci:])
+			}
+			bl := blobs[blobi]
+			if bl.Slot != block.Slot() {
+				return nil, missingCommitError(bb.Block.Root(), commits[ci:])
+			}
+			if bytesutil.ToBytes32(bl.BlockRoot) != bb.Block.Root() {
+				return nil, errors.Wrapf(errMismatchedBlobBlockRoot,
+					"block root %#x != BlobSidecar.BlockRoot %#x at slot %d", bb.Block.Root(), bl.BlockRoot, block.Slot())
+			}
+			if ci != int(bl.Index) {
+				return nil, errors.Wrapf(errMissingBlobIndex,
+					"did not receive blob index %d for block root %#x at slot %d", ci, bb.Block.Root(), block.Slot())
+			}
+			ec := bytesutil.ToBytes48(commits[ci])
+			ac := bytesutil.ToBytes48(bl.KzgCommitment)
+			if ec != ac {
+				return nil, errors.Wrapf(errMismatchedBlobCommitments,
+					"commitment %#x != block commitment %#x, at index %d for block root %#x at slot %d ",
+					ac, ec, bl.Index, bb.Block.Root(), block.Slot())
+			}
+			bb.Blobs[ci] = bl
+			blobi += 1
+		}
+		bwb[i] = bb
+	}
+	return bwb, nil
+}
+
+func missingCommitError(root [32]byte, missing [][]byte) error {
+	missStr := make([]string, len(missing))
+	for k := range missing {
+		missStr = append(missStr, fmt.Sprintf("%#x", k))
+	}
+	return errors.Wrapf(errMissingBlobsForBlockCommitments,
+		"block root %#x missing %d commitments %s", root, len(missing), strings.Join(missStr, ","))
+}
+
+// fetchBlobsFromPeer fetches blocks from a single randomly selected peer.
+func (f *blocksFetcher) fetchBlobsFromPeer(ctx context.Context, bwb []blocks2.BlockWithVerifiedBlobs, pid peer.ID) ([]blocks2.BlockWithVerifiedBlobs, error) {
+	ctx, span := trace.StartSpan(ctx, "initialsync.fetchBlobsFromPeer")
+	defer span.End()
+	if slots.ToEpoch(f.clock.CurrentSlot()) < params.BeaconConfig().DenebForkEpoch {
+		return bwb, nil
+	}
+	blobWindowStart, err := prysmsync.BlobsByRangeMinStartSlot(f.clock.CurrentSlot())
+	if err != nil {
+		return nil, err
+	}
+	// Construct request message based on observed interval of blocks in need of blobs.
+	req := blobRequest(bwb, blobWindowStart)
+	if req == nil {
+		return bwb, nil
+	}
+	// Request blobs from the same peer that gave us the blob batch.
+	blobs, err := f.requestBlobs(ctx, req, pid)
+	if err != nil {
+		return nil, errors.Wrap(err, "could not request blobs by range")
+	}
+	f.p2p.Peers().Scorers().BlockProviderScorer().Touch(pid)
+	return verifyAndPopulateBlobs(bwb, blobs, blobWindowStart)
+}
+
 // requestBlocks is a wrapper for handling BeaconBlocksByRangeRequest requests/streams.
 func (f *blocksFetcher) requestBlocks(
 	ctx context.Context,
@@ -334,6 +520,33 @@ func (f *blocksFetcher) requestBlocks(
 	return prysmsync.SendBeaconBlocksByRangeRequest(ctx, f.chain, f.p2p, pid, req, nil)
 }
 
+func (f *blocksFetcher) requestBlobs(ctx context.Context, req *p2ppb.BlobSidecarsByRangeRequest, pid peer.ID) ([]*p2ppb.BlobSidecar, error) {
+	if ctx.Err() != nil {
+		return nil, ctx.Err()
+	}
+	l := f.peerLock(pid)
+	l.Lock()
+	log.WithFields(logrus.Fields{
+		"peer":     pid,
+		"start":    req.StartSlot,
+		"count":    req.Count,
+		"capacity": f.rateLimiter.Remaining(pid.String()),
+		"score":    f.p2p.Peers().Scorers().BlockProviderScorer().FormatScorePretty(pid),
+	}).Debug("Requesting blobs")
+	// We're intentionally abusing the block rate limit here, treating blob requests as if they were blob requests.
+	// Since blob requests take more bandwidth than blocks, we should improve how we account for the different kinds
+	// of requests, more in proportion to the cost of serving them.
+	if f.rateLimiter.Remaining(pid.String()) < int64(req.Count) {
+		if err := f.waitForBandwidth(pid, req.Count); err != nil {
+			l.Unlock()
+			return nil, err
+		}
+	}
+	f.rateLimiter.Add(pid.String(), int64(req.Count))
+	l.Unlock()
+	return prysmsync.SendBlobsByRangeRequest(ctx, f.clock, f.p2p, pid, f.ctxMap, req)
+}
+
 // requestBlocksByRoot is a wrapper for handling BeaconBlockByRootsReq requests/streams.
 func (f *blocksFetcher) requestBlocksByRoot(
 	ctx context.Context,
diff --git a/beacon-chain/sync/initial-sync/blocks_fetcher_test.go b/beacon-chain/sync/initial-sync/blocks_fetcher_test.go
index 04fa4d2c05..d836642a8b 100644
--- a/beacon-chain/sync/initial-sync/blocks_fetcher_test.go
+++ b/beacon-chain/sync/initial-sync/blocks_fetcher_test.go
@@ -3,6 +3,7 @@ package initialsync
 import (
 	"context"
 	"fmt"
+	"math/rand"
 	"sort"
 	"sync"
 	"testing"
@@ -23,6 +24,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	leakybucket "github.com/prysmaticlabs/prysm/v4/container/leaky-bucket"
 	"github.com/prysmaticlabs/prysm/v4/container/slice"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
 	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 	"github.com/prysmaticlabs/prysm/v4/testing/assert"
 	"github.com/prysmaticlabs/prysm/v4/testing/require"
@@ -273,6 +275,9 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 			st, err := util.NewBeaconState()
 			require.NoError(t, err)
 
+			gt := time.Now()
+			vr := [32]byte{}
+			clock := startup.NewClock(gt, vr)
 			mc := &mock.ChainService{
 				State: st,
 				Root:  genesisRoot[:],
@@ -288,6 +293,7 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 			fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
 				chain: mc,
 				p2p:   p,
+				clock: clock,
 			})
 			require.NoError(t, fetcher.start())
 
@@ -299,9 +305,9 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 				fetcher.stop()
 			}()
 
-			processFetchedBlocks := func() ([]interfaces.ReadOnlySignedBeaconBlock, error) {
+			processFetchedBlocks := func() ([]blocks.BlockWithVerifiedBlobs, error) {
 				defer cancel()
-				var unionRespBlocks []interfaces.ReadOnlySignedBeaconBlock
+				var unionRespBlocks []blocks.BlockWithVerifiedBlobs
 
 				for {
 					select {
@@ -313,8 +319,8 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 						if resp.err != nil {
 							log.WithError(resp.err).Debug("Block fetcher returned error")
 						} else {
-							unionRespBlocks = append(unionRespBlocks, resp.blocks...)
-							if len(resp.blocks) == 0 {
+							unionRespBlocks = append(unionRespBlocks, resp.bwb...)
+							if len(resp.bwb) == 0 {
 								log.WithFields(logrus.Fields{
 									"start": resp.start,
 									"count": resp.count,
@@ -337,30 +343,27 @@ func TestBlocksFetcher_RoundRobin(t *testing.T) {
 				maxExpectedBlocks += requestParams.count
 			}
 
-			blocks, err := processFetchedBlocks()
+			bwb, err := processFetchedBlocks()
 			assert.NoError(t, err)
 
-			sort.Slice(blocks, func(i, j int) bool {
-				return blocks[i].Block().Slot() < blocks[j].Block().Slot()
-			})
-
-			ss := make([]primitives.Slot, len(blocks))
-			for i, block := range blocks {
-				ss[i] = block.Block().Slot()
+			sort.Sort(blocks.BlockWithVerifiedBlobsSlice(bwb))
+			ss := make([]primitives.Slot, len(bwb))
+			for i, b := range bwb {
+				ss[i] = b.Block.Block().Slot()
 			}
 
 			log.WithFields(logrus.Fields{
-				"blocksLen": len(blocks),
+				"blocksLen": len(bwb),
 				"slots":     ss,
 			}).Debug("Finished block fetching")
 
-			if len(blocks) > int(maxExpectedBlocks) {
-				t.Errorf("Too many blocks returned. Wanted %d got %d", maxExpectedBlocks, len(blocks))
+			if len(bwb) > int(maxExpectedBlocks) {
+				t.Errorf("Too many blocks returned. Wanted %d got %d", maxExpectedBlocks, len(bwb))
 			}
-			assert.Equal(t, len(tt.expectedBlockSlots), len(blocks), "Processes wrong number of blocks")
+			assert.Equal(t, len(tt.expectedBlockSlots), len(bwb), "Processes wrong number of blocks")
 			var receivedBlockSlots []primitives.Slot
-			for _, blk := range blocks {
-				receivedBlockSlots = append(receivedBlockSlots, blk.Block().Slot())
+			for _, b := range bwb {
+				receivedBlockSlots = append(receivedBlockSlots, b.Block.Block().Slot())
 			}
 			missing := slice.NotSlot(slice.IntersectionSlot(tt.expectedBlockSlots, receivedBlockSlots), tt.expectedBlockSlots)
 			if len(missing) > 0 {
@@ -417,11 +420,13 @@ func TestBlocksFetcher_handleRequest(t *testing.T) {
 	mc, p2p, _ := initializeTestServices(t, chainConfig.expectedBlockSlots, chainConfig.peers)
 	mc.ValidatorsRoot = [32]byte{}
 	mc.Genesis = time.Now()
+
 	t.Run("context cancellation", func(t *testing.T) {
 		ctx, cancel := context.WithCancel(context.Background())
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
 			chain: mc,
 			p2p:   p2p,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 		})
 
 		cancel()
@@ -435,6 +440,7 @@ func TestBlocksFetcher_handleRequest(t *testing.T) {
 		fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
 			chain: mc,
 			p2p:   p2p,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 		})
 
 		requestCtx, reqCancel := context.WithTimeout(context.Background(), 2*time.Second)
@@ -447,7 +453,7 @@ func TestBlocksFetcher_handleRequest(t *testing.T) {
 			}
 		}()
 
-		var blocks []interfaces.ReadOnlySignedBeaconBlock
+		var bwb []blocks.BlockWithVerifiedBlobs
 		select {
 		case <-ctx.Done():
 			t.Error(ctx.Err())
@@ -455,16 +461,16 @@ func TestBlocksFetcher_handleRequest(t *testing.T) {
 			if resp.err != nil {
 				t.Error(resp.err)
 			} else {
-				blocks = resp.blocks
+				bwb = resp.bwb
 			}
 		}
-		if uint64(len(blocks)) != uint64(blockBatchLimit) {
-			t.Errorf("incorrect number of blocks returned, expected: %v, got: %v", blockBatchLimit, len(blocks))
+		if uint64(len(bwb)) != uint64(blockBatchLimit) {
+			t.Errorf("incorrect number of blocks returned, expected: %v, got: %v", blockBatchLimit, len(bwb))
 		}
 
 		var receivedBlockSlots []primitives.Slot
-		for _, blk := range blocks {
-			receivedBlockSlots = append(receivedBlockSlots, blk.Block().Slot())
+		for _, b := range bwb {
+			receivedBlockSlots = append(receivedBlockSlots, b.Block.Block().Slot())
 		}
 		missing := slice.NotSlot(slice.IntersectionSlot(chainConfig.expectedBlockSlots, receivedBlockSlots), chainConfig.expectedBlockSlots)
 		if len(missing) > 0 {
@@ -952,3 +958,171 @@ func TestTimeToWait(t *testing.T) {
 		})
 	}
 }
+
+func TestSortBlobs(t *testing.T) {
+	_, blobs := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, 10)
+	shuffled := make([]*ethpb.BlobSidecar, len(blobs))
+	for i := range blobs {
+		shuffled[i] = blobs[i]
+	}
+	rand.Shuffle(len(shuffled), func(i, j int) {
+		shuffled[i], shuffled[j] = shuffled[j], shuffled[i]
+	})
+	sorted := sortBlobs(shuffled)
+	require.Equal(t, len(sorted), len(shuffled))
+	for i := range blobs {
+		expect := blobs[i]
+		actual := sorted[i]
+		require.Equal(t, expect.Slot, actual.Slot)
+		require.Equal(t, expect.Index, actual.Index)
+		require.Equal(t, bytesutil.ToBytes48(expect.KzgCommitment), bytesutil.ToBytes48(actual.KzgCommitment))
+		require.Equal(t, bytesutil.ToBytes32(expect.BlockRoot), bytesutil.ToBytes32(actual.BlockRoot))
+	}
+}
+
+func TestLowestSlotNeedsBlob(t *testing.T) {
+	blks, _ := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, 10)
+	sbbs := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
+	for i := range blks {
+		sbbs[i] = blks[i]
+	}
+	retentionStart := primitives.Slot(5)
+	bwb, err := sortedBlockWithVerifiedBlobSlice(sbbs)
+	require.NoError(t, err)
+	lowest := lowestSlotNeedsBlob(retentionStart, bwb)
+	require.Equal(t, retentionStart, *lowest)
+	higher := primitives.Slot(len(blks) + 1)
+	lowest = lowestSlotNeedsBlob(higher, bwb)
+	var nilSlot *primitives.Slot
+	require.Equal(t, nilSlot, lowest)
+
+	blks, _ = util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, 10)
+	sbbs = make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
+	for i := range blks {
+		sbbs[i] = blks[i]
+	}
+	bwb, err = sortedBlockWithVerifiedBlobSlice(sbbs)
+	require.NoError(t, err)
+	retentionStart = bwb[5].Block.Block().Slot()
+	next := bwb[6].Block.Block().Slot()
+	skip := bwb[5].Block.Block()
+	bwb[5].Block, _ = util.GenerateTestDenebBlockWithSidecar(t, skip.ParentRoot(), skip.Slot(), 0)
+	lowest = lowestSlotNeedsBlob(retentionStart, bwb)
+	require.Equal(t, next, *lowest)
+}
+
+func TestBlobRequest(t *testing.T) {
+	var nilReq *ethpb.BlobSidecarsByRangeRequest
+	// no blocks
+	req := blobRequest([]blocks.BlockWithVerifiedBlobs{}, 0)
+	require.Equal(t, nilReq, req)
+	blks, _ := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, 10)
+	sbbs := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
+	for i := range blks {
+		sbbs[i] = blks[i]
+	}
+	bwb, err := sortedBlockWithVerifiedBlobSlice(sbbs)
+	require.NoError(t, err)
+	maxBlkSlot := primitives.Slot(len(blks) - 1)
+
+	tooHigh := primitives.Slot(len(blks) + 1)
+	req = blobRequest(bwb, tooHigh)
+	require.Equal(t, nilReq, req)
+
+	req = blobRequest(bwb, maxBlkSlot)
+	require.Equal(t, uint64(1), req.Count)
+	require.Equal(t, maxBlkSlot, req.StartSlot)
+
+	halfway := primitives.Slot(5)
+	req = blobRequest(bwb, halfway)
+	require.Equal(t, halfway, req.StartSlot)
+	// adding 1 to include the halfway slot itself
+	require.Equal(t, uint64(1+maxBlkSlot-halfway), req.Count)
+
+	before := bwb[0].Block.Block().Slot()
+	allAfter := bwb[1:]
+	req = blobRequest(allAfter, before)
+	require.Equal(t, allAfter[0].Block.Block().Slot(), req.StartSlot)
+	require.Equal(t, len(allAfter), int(req.Count))
+}
+
+func testSequenceBlockWithBlob(t *testing.T, nblocks int) ([]blocks.BlockWithVerifiedBlobs, []*ethpb.BlobSidecar) {
+	blks, blobs := util.ExtendBlocksPlusBlobs(t, []blocks.ROBlock{}, nblocks)
+	sbbs := make([]interfaces.ReadOnlySignedBeaconBlock, len(blks))
+	for i := range blks {
+		sbbs[i] = blks[i]
+	}
+	bwb, err := sortedBlockWithVerifiedBlobSlice(sbbs)
+	require.NoError(t, err)
+	return bwb, blobs
+}
+
+func TestVerifyAndPopulateBlobs(t *testing.T) {
+	bwb, blobs := testSequenceBlockWithBlob(t, 10)
+	lastBlobIdx := len(blobs) - 1
+	// Blocks are all before the retention window, blobs argument is ignored.
+	windowAfter := bwb[len(bwb)-1].Block.Block().Slot() + 1
+	_, err := verifyAndPopulateBlobs(bwb, nil, windowAfter)
+	require.NoError(t, err)
+
+	firstBlockSlot := bwb[0].Block.Block().Slot()
+	// slice off blobs for the last block so we hit the out of bounds / blob exhaustion check.
+	_, err = verifyAndPopulateBlobs(bwb, blobs[0:len(blobs)-6], firstBlockSlot)
+	require.ErrorIs(t, err, errMissingBlobsForBlockCommitments)
+
+	bwb, blobs = testSequenceBlockWithBlob(t, 10)
+	// Misalign the slots of the blobs for the first block to simulate them being missing from the response.
+	offByOne := blobs[0].Slot
+	for i := range blobs {
+		if blobs[i].Slot == offByOne {
+			blobs[i].Slot = offByOne + 1
+		}
+	}
+	_, err = verifyAndPopulateBlobs(bwb, blobs, firstBlockSlot)
+	require.ErrorIs(t, err, errMissingBlobsForBlockCommitments)
+
+	bwb, blobs = testSequenceBlockWithBlob(t, 10)
+	blobs[lastBlobIdx].BlockRoot = blobs[0].BlockRoot
+	_, err = verifyAndPopulateBlobs(bwb, blobs, firstBlockSlot)
+	require.ErrorIs(t, err, errMismatchedBlobBlockRoot)
+
+	bwb, blobs = testSequenceBlockWithBlob(t, 10)
+	blobs[lastBlobIdx].Index = 100
+	_, err = verifyAndPopulateBlobs(bwb, blobs, firstBlockSlot)
+	require.ErrorIs(t, err, errMissingBlobIndex)
+
+	var emptyKzg [48]byte
+	bwb, blobs = testSequenceBlockWithBlob(t, 10)
+	blobs[lastBlobIdx].KzgCommitment = emptyKzg[:]
+	_, err = verifyAndPopulateBlobs(bwb, blobs, firstBlockSlot)
+	require.ErrorIs(t, err, errMismatchedBlobCommitments)
+
+	// happy path
+	bwb, blobs = testSequenceBlockWithBlob(t, 10)
+
+	expectedCommits := make(map[[48]byte]bool)
+	for _, bl := range blobs {
+		expectedCommits[bytesutil.ToBytes48(bl.KzgCommitment)] = true
+	}
+	// The assertions using this map expect all commitments to be unique, so make sure that stays true.
+	require.Equal(t, len(blobs), len(expectedCommits))
+
+	bwb, err = verifyAndPopulateBlobs(bwb, blobs, firstBlockSlot)
+	require.NoError(t, err)
+	for _, bw := range bwb {
+		commits, err := bw.Block.Block().Body().BlobKzgCommitments()
+		require.NoError(t, err)
+		require.Equal(t, len(commits), len(bw.Blobs))
+		for i := range commits {
+			bc := bytesutil.ToBytes48(commits[i])
+			require.Equal(t, bc, bytesutil.ToBytes48(bw.Blobs[i].KzgCommitment))
+			// Since we delete entries we've seen, duplicates will cause an error here.
+			_, ok := expectedCommits[bc]
+			// Make sure this was an expected delete, then delete it from the map so we can make sure we saw all of them.
+			require.Equal(t, true, ok)
+			delete(expectedCommits, bc)
+		}
+	}
+	// We delete each entry we've seen, so if we see all expected commits, the map should be empty at the end.
+	require.Equal(t, 0, len(expectedCommits))
+}
diff --git a/beacon-chain/sync/initial-sync/blocks_fetcher_utils.go b/beacon-chain/sync/initial-sync/blocks_fetcher_utils.go
index 93d3e360df..b80c546350 100644
--- a/beacon-chain/sync/initial-sync/blocks_fetcher_utils.go
+++ b/beacon-chain/sync/initial-sync/blocks_fetcher_utils.go
@@ -3,13 +3,13 @@ package initialsync
 import (
 	"context"
 	"fmt"
-	"sort"
 
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/pkg/errors"
 	p2pTypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/types"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	p2ppb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
@@ -22,8 +22,8 @@ import (
 // Blocks are stored in an ascending slot order. The first block is guaranteed to have parent
 // either in DB or initial sync cache.
 type forkData struct {
-	peer   peer.ID
-	blocks []interfaces.ReadOnlySignedBeaconBlock
+	peer peer.ID
+	bwb  []blocks.BlockWithVerifiedBlobs
 }
 
 // nonSkippedSlotAfter checks slots after the given one in an attempt to find a non-empty future slot.
@@ -200,13 +200,20 @@ func (f *blocksFetcher) findFork(ctx context.Context, slot primitives.Slot) (*fo
 	return nil, errNoPeersWithAltBlocks
 }
 
+var errNoAlternateBlocks = errors.New("no alternative blocks exist within scanned range")
+
+func findForkReqRangeSize() uint64 {
+	return uint64(params.BeaconConfig().SlotsPerEpoch.Mul(2))
+}
+
 // findForkWithPeer loads some blocks from a peer in an attempt to find alternative blocks.
 func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot primitives.Slot) (*forkData, error) {
+	reqCount := findForkReqRangeSize()
 	// Safe-guard, since previous epoch is used when calculating.
-	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
-	if slot < slotsPerEpoch*2 {
-		return nil, fmt.Errorf("slot is too low to backtrack, min. expected %d", slotsPerEpoch*2)
+	if uint64(slot) < reqCount {
+		return nil, fmt.Errorf("slot is too low to backtrack, min. expected %d", reqCount)
 	}
+	slotsPerEpoch := params.BeaconConfig().SlotsPerEpoch
 
 	// Locate non-skipped slot, supported by a given peer (can survive long periods of empty slots).
 	// When searching for non-empty slot, start an epoch earlier - for those blocks we
@@ -226,37 +233,62 @@ func (f *blocksFetcher) findForkWithPeer(ctx context.Context, pid peer.ID, slot
 	// Request blocks starting from the first non-empty slot.
 	req := &p2ppb.BeaconBlocksByRangeRequest{
 		StartSlot: nonSkippedSlot,
-		Count:     uint64(slotsPerEpoch.Mul(2)),
+		Count:     reqCount,
 		Step:      1,
 	}
 	blocks, err := f.requestBlocks(ctx, req, pid)
 	if err != nil {
 		return nil, fmt.Errorf("cannot fetch blocks: %w", err)
 	}
+	if len(blocks) == 0 {
+		return nil, errNoAlternateBlocks
+	}
+
+	// If the first block is not connected to the current canonical chain, we'll stop processing this batch.
+	// Instead, we'll work backwards from the first block until we find a common ancestor,
+	// and then begin processing from there.
+	first := blocks[0]
+	if !f.chain.HasBlock(ctx, first.Block().ParentRoot()) {
+		// Backtrack on a root, to find a common ancestor from which we can resume syncing.
+		fork, err := f.findAncestor(ctx, pid, first)
+		if err != nil {
+			return nil, fmt.Errorf("failed to find common ancestor: %w", err)
+		}
+		return fork, nil
+	}
 
 	// Traverse blocks, and if we've got one that doesn't have parent in DB, backtrack on it.
-	for i, block := range blocks {
+	// Note that we start from the second element in the array, because we know that the first element is in the db,
+	// otherwise we would have gone into the findAncestor early return path above.
+	for i := 1; i < len(blocks); i++ {
+		block := blocks[i]
 		parentRoot := block.Block().ParentRoot()
-		if !f.chain.HasBlock(ctx, parentRoot) {
-			log.WithFields(logrus.Fields{
-				"peer": pid,
-				"slot": block.Block().Slot(),
-				"root": fmt.Sprintf("%#x", parentRoot),
-			}).Debug("Block with unknown parent root has been found")
-			// Backtrack only if the first block is diverging,
-			// otherwise we already know the common ancestor slot.
-			if i == 0 {
-				// Backtrack on a root, to find a common ancestor from which we can resume syncing.
-				fork, err := f.findAncestor(ctx, pid, block)
-				if err != nil {
-					return nil, fmt.Errorf("failed to find common ancestor: %w", err)
-				}
-				return fork, nil
-			}
-			return &forkData{peer: pid, blocks: blocks}, nil
+		// Step through blocks until we find one that is not in the chain. The goal is to find the point where the
+		// chain observed in the peer diverges from the locally known chain, and then collect up the remainder of the
+		// observed chain chunk to start initial-sync processing from the fork point.
+		if f.chain.HasBlock(ctx, parentRoot) {
+			continue
 		}
+		log.WithFields(logrus.Fields{
+			"peer": pid,
+			"slot": block.Block().Slot(),
+			"root": fmt.Sprintf("%#x", parentRoot),
+		}).Debug("Block with unknown parent root has been found")
+		altBlocks, err := sortedBlockWithVerifiedBlobSlice(blocks[i-1:])
+		if err != nil {
+			return nil, errors.Wrap(err, "invalid blocks received in findForkWithPeer")
+		}
+		// We need to fetch the blobs for the given alt-chain if any exist, so that we can try to verify and import
+		// the blocks.
+		bwb, err := f.fetchBlobsFromPeer(ctx, altBlocks, pid)
+		if err != nil {
+			return nil, errors.Wrap(err, "unable to retrieve blobs for blocks found in findForkWithPeer")
+		}
+		// The caller will use the BlocksWith VerifiedBlobs in bwb as the starting point for
+		// round-robin syncing the alternate chain.
+		return &forkData{peer: pid, bwb: bwb}, nil
 	}
-	return nil, errors.New("no alternative blocks exist within scanned range")
+	return nil, errNoAlternateBlocks
 }
 
 // findAncestor tries to figure out common ancestor slot that connects a given root to known block.
@@ -266,12 +298,17 @@ func (f *blocksFetcher) findAncestor(ctx context.Context, pid peer.ID, b interfa
 		parentRoot := outBlocks[len(outBlocks)-1].Block().ParentRoot()
 		if f.chain.HasBlock(ctx, parentRoot) {
 			// Common ancestor found, forward blocks back to processor.
-			sort.Slice(outBlocks, func(i, j int) bool {
-				return outBlocks[i].Block().Slot() < outBlocks[j].Block().Slot()
-			})
+			bwb, err := sortedBlockWithVerifiedBlobSlice(outBlocks)
+			if err != nil {
+				return nil, errors.Wrap(err, "received invalid blocks in findAncestor")
+			}
+			bwb, err = f.fetchBlobsFromPeer(ctx, bwb, pid)
+			if err != nil {
+				return nil, errors.Wrap(err, "unable to retrieve blobs for blocks found in findAncestor")
+			}
 			return &forkData{
-				peer:   pid,
-				blocks: outBlocks,
+				peer: pid,
+				bwb:  bwb,
 			}, nil
 		}
 		// Request block's parent.
diff --git a/beacon-chain/sync/initial-sync/blocks_fetcher_utils_test.go b/beacon-chain/sync/initial-sync/blocks_fetcher_utils_test.go
index b58fb07339..9f225fb4e7 100644
--- a/beacon-chain/sync/initial-sync/blocks_fetcher_utils_test.go
+++ b/beacon-chain/sync/initial-sync/blocks_fetcher_utils_test.go
@@ -13,6 +13,8 @@ import (
 	dbtest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	p2pm "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
 	p2pt "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/testing"
+	p2pTypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/types"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -187,6 +189,7 @@ func TestBlocksFetcher_findFork(t *testing.T) {
 		ctx,
 		&blocksFetcherConfig{
 			chain: mc,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 			p2p:   p2p,
 			db:    beaconDB,
 		},
@@ -252,10 +255,14 @@ func TestBlocksFetcher_findFork(t *testing.T) {
 	// is smart enough to link back to common ancestor, w/o discriminating between forks. This is
 	// by design: fork exploration is undertaken when FSMs are stuck, so any progress is good.
 	chain1b := extendBlockSequence(t, chain1, 64)
+	forkSlot1b := primitives.Slot(len(chain1))
 	curForkMoreBlocksPeer := connectPeerHavingBlocks(t, p2p, chain1b, finalizedSlot, p2p.Peers())
 	fork, err = fetcher.findFork(ctx, 251)
 	require.NoError(t, err)
-	require.Equal(t, 64, len(fork.blocks))
+
+	reqEnd := testForkStartSlot(t, 251) + primitives.Slot(findForkReqRangeSize())
+	require.Equal(t, primitives.Slot(len(chain1)), fork.bwb[0].Block.Block().Slot())
+	require.Equal(t, int(reqEnd-forkSlot1b), len(fork.bwb))
 	require.Equal(t, curForkMoreBlocksPeer, fork.peer)
 	// Save all chain1b blocks (so that they do not interfere with alternative fork)
 	for _, blk := range chain1b {
@@ -277,20 +284,20 @@ func TestBlocksFetcher_findFork(t *testing.T) {
 	fork, err = fetcher.findFork(ctx, 251)
 	require.NoError(t, err)
 	assert.Equal(t, alternativePeer, fork.peer)
-	assert.Equal(t, 65, len(fork.blocks))
+	assert.Equal(t, 65, len(fork.bwb))
 	ind := forkSlot
-	for _, blk := range fork.blocks {
-		require.Equal(t, blk.Block().Slot(), chain2[ind].Block.Slot)
+	for _, blk := range fork.bwb {
+		require.Equal(t, blk.Block.Block().Slot(), chain2[ind].Block.Slot)
 		ind++
 	}
 
 	// Process returned blocks and then attempt to extend chain (ensuring that parent block exists).
-	for _, blk := range fork.blocks {
-		require.NoError(t, beaconDB.SaveBlock(ctx, blk))
-		require.NoError(t, st.SetSlot(blk.Block().Slot()))
+	for _, blk := range fork.bwb {
+		require.NoError(t, beaconDB.SaveBlock(ctx, blk.Block))
+		require.NoError(t, st.SetSlot(blk.Block.Block().Slot()))
 	}
-	assert.Equal(t, forkSlot.Add(uint64(len(fork.blocks)-1)), mc.HeadSlot())
-	for i := forkSlot.Add(uint64(len(fork.blocks))); i < primitives.Slot(len(chain2)); i++ {
+	assert.Equal(t, forkSlot.Add(uint64(len(fork.bwb)-1)), mc.HeadSlot())
+	for i := forkSlot.Add(uint64(len(fork.bwb))); i < primitives.Slot(len(chain2)); i++ {
 		blk := chain2[i]
 		require.Equal(t, blk.Block.Slot, i, "incorrect block selected for slot %d", i)
 		// Only save is parent block exists.
@@ -309,6 +316,21 @@ func TestBlocksFetcher_findFork(t *testing.T) {
 	}
 }
 
+func testForkStartSlot(t *testing.T, slot primitives.Slot) primitives.Slot {
+	// When we call find fork, the way we find the first common ancestor is:
+	// - start at the first slot of the given epoch (epochStart below)
+	// - look back an additional epoch, which findForkWithPeer comments say is done to ensure
+	//   there will be more overlap, since this routine kicks off when we're losing sight of the canonical chain
+	// - add one: this happens in nonSkippedSlotAfterWithPeersTarget and isn't really explained why this method takes
+	//   the slot before the beginning of the search range and not the actual search range.
+	// Anyway, since findFork returns the last common ancestor between the known chain and the forked chain,
+	// we need to figure out how much the two overlap so we can ignore the common blocks when looking at the
+	// size of the response.
+	epochStart, err := slots.EpochStart(slots.ToEpoch(slot))
+	require.NoError(t, err)
+	return 1 + (epochStart - params.BeaconConfig().SlotsPerEpoch)
+}
+
 func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 	beaconDB := dbtest.SetupDB(t)
 	p1 := p2pt.NewTestP2P(t)
@@ -335,6 +357,7 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		ctx,
 		&blocksFetcherConfig{
 			chain: mc,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 			p2p:   p1,
 			db:    beaconDB,
 		},
@@ -392,8 +415,8 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		}()
 		fork, err := fetcher.findForkWithPeer(ctx, p2, 64)
 		require.NoError(t, err)
-		require.Equal(t, 10, len(fork.blocks))
-		assert.Equal(t, forkedSlot, fork.blocks[0].Block().Slot(), "Expected slot %d to be ancestor", forkedSlot)
+		require.Equal(t, 10, len(fork.bwb))
+		assert.Equal(t, forkedSlot, fork.bwb[0].Block.Block().Slot(), "Expected slot %d to be ancestor", forkedSlot)
 	})
 
 	t.Run("first block is diverging - no common ancestor", func(t *testing.T) {
@@ -417,11 +440,32 @@ func TestBlocksFetcher_findForkWithPeer(t *testing.T) {
 		}()
 		fork, err := fetcher.findForkWithPeer(ctx, p2, 64)
 		require.NoError(t, err)
-		require.Equal(t, 64, len(fork.blocks))
-		assert.Equal(t, primitives.Slot(33), fork.blocks[0].Block().Slot())
+
+		reqEnd := testForkStartSlot(t, 64) + primitives.Slot(findForkReqRangeSize())
+		expectedLen := reqEnd - forkedSlot
+		// there are 4 blocks that are different before the beginning
+		require.Equal(t, int(expectedLen), len(fork.bwb))
+		assert.Equal(t, primitives.Slot(60), fork.bwb[0].Block.Block().Slot())
 	})
 }
 
+func TestTestForkStartSlot(t *testing.T) {
+	require.Equal(t, primitives.Slot(33), testForkStartSlot(t, 64))
+	require.Equal(t, primitives.Slot(193), testForkStartSlot(t, 251))
+}
+
+func consumeBlockRootRequest(t *testing.T, p *p2pt.TestP2P) func(network.Stream) {
+	return func(stream network.Stream) {
+		defer func() {
+			_err := stream.Close()
+			_ = _err
+		}()
+
+		req := new(p2pTypes.BeaconBlockByRootsReq)
+		assert.NoError(t, p.Encoding().DecodeWithMaxLength(stream, req))
+	}
+}
+
 func TestBlocksFetcher_findAncestor(t *testing.T) {
 	beaconDB := dbtest.SetupDB(t)
 	p2p := p2pt.NewTestP2P(t)
@@ -476,9 +520,7 @@ func TestBlocksFetcher_findAncestor(t *testing.T) {
 		p2 := p2pt.NewTestP2P(t)
 		p2p.Connect(p2)
 
-		p2.SetStreamHandler(pcl, func(stream network.Stream) {
-			assert.NoError(t, stream.Close())
-		})
+		p2.SetStreamHandler(pcl, consumeBlockRootRequest(t, p2))
 
 		wsb, err := blocks.NewSignedBeaconBlock(knownBlocks[4])
 		require.NoError(t, err)
diff --git a/beacon-chain/sync/initial-sync/blocks_queue.go b/beacon-chain/sync/initial-sync/blocks_queue.go
index 68e5d3286e..628be0eb17 100644
--- a/beacon-chain/sync/initial-sync/blocks_queue.go
+++ b/beacon-chain/sync/initial-sync/blocks_queue.go
@@ -8,8 +8,9 @@ import (
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
 	beaconsync "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync"
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 	"github.com/sirupsen/logrus"
@@ -62,6 +63,8 @@ type syncMode uint8
 type blocksQueueConfig struct {
 	blocksFetcher       *blocksFetcher
 	chain               blockchainService
+	clock               *startup.Clock
+	ctxMap              beaconsync.ContextByteVersions
 	highestExpectedSlot primitives.Slot
 	p2p                 p2p.P2P
 	db                  db.ReadOnlyDatabase
@@ -88,8 +91,8 @@ type blocksQueue struct {
 
 // blocksQueueFetchedData is a data container that is returned from a queue on each step.
 type blocksQueueFetchedData struct {
-	pid    peer.ID
-	blocks []interfaces.ReadOnlySignedBeaconBlock
+	pid peer.ID
+	bwb []blocks.BlockWithVerifiedBlobs
 }
 
 // newBlocksQueue creates initialized priority queue.
@@ -99,9 +102,11 @@ func newBlocksQueue(ctx context.Context, cfg *blocksQueueConfig) *blocksQueue {
 	blocksFetcher := cfg.blocksFetcher
 	if blocksFetcher == nil {
 		blocksFetcher = newBlocksFetcher(ctx, &blocksFetcherConfig{
-			chain: cfg.chain,
-			p2p:   cfg.p2p,
-			db:    cfg.db,
+			ctxMap: cfg.ctxMap,
+			chain:  cfg.chain,
+			p2p:    cfg.p2p,
+			db:     cfg.db,
+			clock:  cfg.clock,
 		})
 	}
 	highestExpectedSlot := cfg.highestExpectedSlot
@@ -316,15 +321,15 @@ func (q *blocksQueue) onDataReceivedEvent(ctx context.Context) eventHandlerFn {
 			return m.state, errInputNotFetchRequestParams
 		}
 		if response.err != nil {
-			switch response.err {
-			case errSlotIsTooHigh:
+			if errors.Is(response.err, errSlotIsTooHigh) {
 				// Current window is already too big, re-request previous epochs.
 				for _, fsm := range q.smm.machines {
 					if fsm.start < response.start && fsm.state == stateSkipped {
 						fsm.setState(stateNew)
 					}
 				}
-			case beaconsync.ErrInvalidFetchedData:
+			}
+			if errors.Is(response.err, beaconsync.ErrInvalidFetchedData) {
 				// Peer returned invalid data, penalize.
 				q.blocksFetcher.p2p.Peers().Scorers().BadResponsesScorer().Increment(m.pid)
 				log.WithField("pid", response.pid).Debug("Peer is penalized for invalid blocks")
@@ -332,7 +337,7 @@ func (q *blocksQueue) onDataReceivedEvent(ctx context.Context) eventHandlerFn {
 			return m.state, response.err
 		}
 		m.pid = response.pid
-		m.blocks = response.blocks
+		m.bwb = response.bwb
 		return stateDataParsed, nil
 	}
 }
@@ -347,14 +352,14 @@ func (q *blocksQueue) onReadyToSendEvent(ctx context.Context) eventHandlerFn {
 			return m.state, errInvalidInitialState
 		}
 
-		if len(m.blocks) == 0 {
+		if len(m.bwb) == 0 {
 			return stateSkipped, nil
 		}
 
 		send := func() (stateID, error) {
 			data := &blocksQueueFetchedData{
-				pid:    m.pid,
-				blocks: m.blocks,
+				pid: m.pid,
+				bwb: m.bwb,
 			}
 			select {
 			case <-ctx.Done():
diff --git a/beacon-chain/sync/initial-sync/blocks_queue_test.go b/beacon-chain/sync/initial-sync/blocks_queue_test.go
index 65e5cb86e2..87610368bf 100644
--- a/beacon-chain/sync/initial-sync/blocks_queue_test.go
+++ b/beacon-chain/sync/initial-sync/blocks_queue_test.go
@@ -11,6 +11,7 @@ import (
 	dbtest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/peers"
 	p2pt "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
 	beaconsync "github.com/prysmaticlabs/prysm/v4/beacon-chain/sync"
 	"github.com/prysmaticlabs/prysm/v4/cmd/beacon-chain/flags"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
@@ -37,6 +38,7 @@ func TestBlocksQueue_InitStartStop(t *testing.T) {
 	fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
 		chain: mc,
 		p2p:   p2p,
+		clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 	})
 
 	t.Run("stop without start", func(t *testing.T) {
@@ -126,6 +128,7 @@ func TestBlocksQueue_InitStartStop(t *testing.T) {
 			blocksFetcher:       fetcher,
 			chain:               mc,
 			highestExpectedSlot: primitives.Slot(blockBatchLimit),
+			clock:               startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 		})
 		assert.NoError(t, queue.start())
 		cancel()
@@ -252,6 +255,7 @@ func TestBlocksQueue_Loop(t *testing.T) {
 			fetcher := newBlocksFetcher(ctx, &blocksFetcherConfig{
 				chain: mc,
 				p2p:   p2p,
+				clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 			})
 			queue := newBlocksQueue(ctx, &blocksQueueConfig{
 				blocksFetcher:       fetcher,
@@ -259,7 +263,8 @@ func TestBlocksQueue_Loop(t *testing.T) {
 				highestExpectedSlot: tt.highestExpectedSlot,
 			})
 			assert.NoError(t, queue.start())
-			processBlock := func(block interfaces.ReadOnlySignedBeaconBlock) error {
+			processBlock := func(b blocks.BlockWithVerifiedBlobs) error {
+				block := b.Block
 				if !beaconDB.HasBlock(ctx, block.Block().ParentRoot()) {
 					return fmt.Errorf("%w: %#x", errParentDoesNotExist, block.Block().ParentRoot())
 				}
@@ -270,13 +275,13 @@ func TestBlocksQueue_Loop(t *testing.T) {
 				return mc.ReceiveBlock(ctx, block, root)
 			}
 
-			var blocks []interfaces.ReadOnlySignedBeaconBlock
+			var blocks []blocks.BlockWithVerifiedBlobs
 			for data := range queue.fetchedData {
-				for _, block := range data.blocks {
-					if err := processBlock(block); err != nil {
+				for _, b := range data.bwb {
+					if err := processBlock(b); err != nil {
 						continue
 					}
-					blocks = append(blocks, block)
+					blocks = append(blocks, b)
 				}
 			}
 
@@ -288,8 +293,8 @@ func TestBlocksQueue_Loop(t *testing.T) {
 			}
 			assert.Equal(t, len(tt.expectedBlockSlots), len(blocks), "Processes wrong number of blocks")
 			var receivedBlockSlots []primitives.Slot
-			for _, blk := range blocks {
-				receivedBlockSlots = append(receivedBlockSlots, blk.Block().Slot())
+			for _, b := range blocks {
+				receivedBlockSlots = append(receivedBlockSlots, b.Block.Block().Slot())
 			}
 			missing := slice.NotSlot(slice.IntersectionSlot(tt.expectedBlockSlots, receivedBlockSlots), tt.expectedBlockSlots)
 			if len(missing) > 0 {
@@ -533,21 +538,21 @@ func TestBlocksQueue_onDataReceivedEvent(t *testing.T) {
 		require.NoError(t, err)
 		response := &fetchRequestResponse{
 			pid: "abc",
-			blocks: []interfaces.ReadOnlySignedBeaconBlock{
-				wsb,
-				wsbCopy,
+			bwb: []blocks.BlockWithVerifiedBlobs{
+				{Block: blocks.ROBlock{ReadOnlySignedBeaconBlock: wsb}},
+				{Block: blocks.ROBlock{ReadOnlySignedBeaconBlock: wsbCopy}},
 			},
 		}
 		fsm := &stateMachine{
 			state: stateScheduled,
 		}
 		assert.Equal(t, peer.ID(""), fsm.pid)
-		assert.DeepSSZEqual(t, []interfaces.ReadOnlySignedBeaconBlock(nil), fsm.blocks)
+		assert.Equal(t, 0, len(fsm.bwb))
 		updatedState, err := handlerFn(fsm, response)
 		assert.NoError(t, err)
 		assert.Equal(t, stateDataParsed, updatedState)
 		assert.Equal(t, response.pid, fsm.pid)
-		assert.DeepSSZEqual(t, response.blocks, fsm.blocks)
+		assert.DeepSSZEqual(t, response.bwb, fsm.bwb)
 	})
 }
 
@@ -631,8 +636,10 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.addStateMachine(320)
 		queue.smm.machines[256].state = stateDataParsed
 		queue.smm.machines[256].pid = pidDataParsed
-		queue.smm.machines[256].blocks = []interfaces.ReadOnlySignedBeaconBlock{
-			wsb,
+		rwsb, err := blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		queue.smm.machines[256].bwb = []blocks.BlockWithVerifiedBlobs{
+			{Block: rwsb},
 		}
 
 		handlerFn := queue.onReadyToSendEvent(ctx)
@@ -663,8 +670,10 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.addStateMachine(320)
 		queue.smm.machines[320].state = stateDataParsed
 		queue.smm.machines[320].pid = pidDataParsed
-		queue.smm.machines[320].blocks = []interfaces.ReadOnlySignedBeaconBlock{
-			wsb,
+		rwsb, err := blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		queue.smm.machines[320].bwb = []blocks.BlockWithVerifiedBlobs{
+			{Block: rwsb},
 		}
 
 		handlerFn := queue.onReadyToSendEvent(ctx)
@@ -692,8 +701,10 @@ func TestBlocksQueue_onReadyToSendEvent(t *testing.T) {
 		queue.smm.addStateMachine(320)
 		queue.smm.machines[320].state = stateDataParsed
 		queue.smm.machines[320].pid = pidDataParsed
-		queue.smm.machines[320].blocks = []interfaces.ReadOnlySignedBeaconBlock{
-			wsb,
+		rwsb, err := blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		queue.smm.machines[320].bwb = []blocks.BlockWithVerifiedBlobs{
+			{Block: rwsb},
 		}
 
 		handlerFn := queue.onReadyToSendEvent(ctx)
@@ -1078,6 +1089,7 @@ func TestBlocksQueue_stuckInUnfavourableFork(t *testing.T) {
 			chain: mc,
 			p2p:   p2p,
 			db:    beaconDB,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)
@@ -1212,27 +1224,28 @@ func TestBlocksQueue_stuckInUnfavourableFork(t *testing.T) {
 		// required forked data, including data on and after slot 201.
 		forkedEpochStartSlot, err := slots.EpochStart(slots.ToEpoch(forkedSlot))
 		require.NoError(t, err)
-		firstFSM, ok := queue.smm.findStateMachine(forkedEpochStartSlot + 1)
+		firstFSM, ok := queue.smm.findStateMachine(forkedSlot)
 		require.Equal(t, true, ok)
 		require.Equal(t, stateDataParsed, firstFSM.state)
 		require.Equal(t, forkedPeer, firstFSM.pid)
-		require.Equal(t, 64, len(firstFSM.blocks))
-		require.Equal(t, forkedEpochStartSlot+1, firstFSM.blocks[0].Block().Slot())
+		reqEnd := testForkStartSlot(t, 251) + primitives.Slot(findForkReqRangeSize())
+		require.Equal(t, int(reqEnd-forkedSlot), len(firstFSM.bwb))
+		require.Equal(t, forkedSlot, firstFSM.bwb[0].Block.Block().Slot())
 
 		// Assert that forked data from chain2 is available (within 64 fetched blocks).
-		for i, blk := range chain2[forkedEpochStartSlot+1:] {
-			if i >= len(firstFSM.blocks) {
+		for i, blk := range chain2[forkedSlot:] {
+			if i >= len(firstFSM.bwb) {
 				break
 			}
-			rootFromFSM, err := firstFSM.blocks[i].Block().HashTreeRoot()
-			require.NoError(t, err)
+			rootFromFSM := firstFSM.bwb[i].Block.Root()
 			blkRoot, err := blk.Block.HashTreeRoot()
 			require.NoError(t, err)
 			assert.Equal(t, blkRoot, rootFromFSM)
 		}
 
 		// Assert that machines are in the expected state.
-		startSlot = forkedEpochStartSlot.Add(1 + uint64(len(firstFSM.blocks)))
+		startSlot = forkedEpochStartSlot.Add(1 + blocksPerRequest)
+		require.Equal(t, int(blocksPerRequest)-int(forkedSlot-(forkedEpochStartSlot+1)), len(firstFSM.bwb))
 		for i := startSlot; i < startSlot.Add(blocksPerRequest*(lookaheadSteps-1)); i += primitives.Slot(blocksPerRequest) {
 			fsm, ok := queue.smm.findStateMachine(i)
 			require.Equal(t, true, ok)
@@ -1298,6 +1311,7 @@ func TestBlocksQueue_stuckWhenHeadIsSetToOrphanedBlock(t *testing.T) {
 			chain: mc,
 			p2p:   p2p,
 			db:    beaconDB,
+			clock: startup.NewClock(mc.Genesis, mc.ValidatorsRoot),
 		},
 	)
 	fetcher.rateLimiter = leakybucket.NewCollector(6400, 6400, 1*time.Second, false)
@@ -1333,7 +1347,8 @@ func TestBlocksQueue_stuckWhenHeadIsSetToOrphanedBlock(t *testing.T) {
 	case <-time.After(3 * time.Second):
 		t.Fatal("test takes too long to complete")
 	case data := <-queue.fetchedData:
-		for _, blk := range data.blocks {
+		for _, b := range data.bwb {
+			blk := b.Block
 			blkRoot, err := blk.Block().HashTreeRoot()
 			require.NoError(t, err)
 			if isProcessedBlock(ctx, blk, blkRoot) {
diff --git a/beacon-chain/sync/initial-sync/blocks_queue_utils.go b/beacon-chain/sync/initial-sync/blocks_queue_utils.go
index 9d5ce7ca18..ceb9e2e5f5 100644
--- a/beacon-chain/sync/initial-sync/blocks_queue_utils.go
+++ b/beacon-chain/sync/initial-sync/blocks_queue_utils.go
@@ -14,13 +14,10 @@ func (q *blocksQueue) resetFromFork(fork *forkData) error {
 	if fork == nil {
 		return errors.New("nil fork data")
 	}
-	if len(fork.blocks) == 0 {
+	if len(fork.bwb) == 0 {
 		return errors.New("no blocks to reset from")
 	}
-	firstBlock := fork.blocks[0].Block()
-	if firstBlock == nil || firstBlock.IsNil() {
-		return errors.New("invalid first block in fork data")
-	}
+	firstBlock := fork.bwb[0].Block.Block()
 
 	blocksPerRequest := q.blocksFetcher.blocksPerPeriod
 	if err := q.smm.removeAllStateMachines(); err != nil {
@@ -28,11 +25,11 @@ func (q *blocksQueue) resetFromFork(fork *forkData) error {
 	}
 	fsm := q.smm.addStateMachine(firstBlock.Slot())
 	fsm.pid = fork.peer
-	fsm.blocks = fork.blocks
+	fsm.bwb = fork.bwb
 	fsm.state = stateDataParsed
 
 	// The rest of machines are in skipped state.
-	startSlot := firstBlock.Slot().Add(uint64(len(fork.blocks)))
+	startSlot := firstBlock.Slot().Add(uint64(len(fork.bwb)))
 	for i := startSlot; i < startSlot.Add(blocksPerRequest*(lookaheadSteps-1)); i += primitives.Slot(blocksPerRequest) {
 		fsm := q.smm.addStateMachine(i)
 		fsm.state = stateSkipped
diff --git a/beacon-chain/sync/initial-sync/fsm.go b/beacon-chain/sync/initial-sync/fsm.go
index 1a2441a0f7..9f3be7f561 100644
--- a/beacon-chain/sync/initial-sync/fsm.go
+++ b/beacon-chain/sync/initial-sync/fsm.go
@@ -7,7 +7,7 @@ import (
 	"time"
 
 	"github.com/libp2p/go-libp2p/core/peer"
-	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	prysmTime "github.com/prysmaticlabs/prysm/v4/time"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
@@ -46,7 +46,7 @@ type stateMachine struct {
 	start   primitives.Slot
 	state   stateID
 	pid     peer.ID
-	blocks  []interfaces.ReadOnlySignedBeaconBlock
+	bwb     []blocks.BlockWithVerifiedBlobs
 	updated time.Time
 }
 
@@ -78,7 +78,7 @@ func (smm *stateMachineManager) addStateMachine(startSlot primitives.Slot) *stat
 		smm:     smm,
 		start:   startSlot,
 		state:   stateNew,
-		blocks:  []interfaces.ReadOnlySignedBeaconBlock{},
+		bwb:     []blocks.BlockWithVerifiedBlobs{},
 		updated: prysmTime.Now(),
 	}
 	smm.recalculateMachineAttribs()
@@ -90,7 +90,7 @@ func (smm *stateMachineManager) removeStateMachine(startSlot primitives.Slot) er
 	if _, ok := smm.machines[startSlot]; !ok {
 		return fmt.Errorf("state for machine %v is not found", startSlot)
 	}
-	smm.machines[startSlot].blocks = nil
+	smm.machines[startSlot].bwb = nil
 	delete(smm.machines, startSlot)
 	smm.recalculateMachineAttribs()
 	return nil
diff --git a/beacon-chain/sync/initial-sync/round_robin.go b/beacon-chain/sync/initial-sync/round_robin.go
index 71fb6160ce..b9c0b32c2f 100644
--- a/beacon-chain/sync/initial-sync/round_robin.go
+++ b/beacon-chain/sync/initial-sync/round_robin.go
@@ -3,13 +3,15 @@ package initialsync
 import (
 	"context"
 	"encoding/hex"
-	"errors"
 	"fmt"
 	"time"
 
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/paulbellamy/ratecounter"
+	"github.com/pkg/errors"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/core/transition"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/sync"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
@@ -25,7 +27,7 @@ const (
 type blockReceiverFn func(ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error
 
 // batchBlockReceiverFn defines batch receiving function.
-type batchBlockReceiverFn func(ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock, roots [][32]byte) error
+type batchBlockReceiverFn func(ctx context.Context, blks []blocks.ROBlock) error
 
 // Round Robin sync looks at the latest peer statuses and syncs up to the highest known epoch.
 //
@@ -69,10 +71,18 @@ func (s *Service) syncToFinalizedEpoch(ctx context.Context, genesis time.Time) e
 		log.Debug("Already synced to finalized epoch")
 		return nil
 	}
+
+	vr := s.clock.GenesisValidatorsRoot()
+	ctxMap, err := sync.ContextByteVersionsForValRoot(vr)
+	if err != nil {
+		return errors.Wrapf(err, "unable to initialize context version map using genesis validator root = %#x", vr)
+	}
 	queue := newBlocksQueue(ctx, &blocksQueueConfig{
 		p2p:                 s.cfg.P2P,
 		db:                  s.cfg.DB,
 		chain:               s.cfg.Chain,
+		clock:               s.clock,
+		ctxMap:              ctxMap,
 		highestExpectedSlot: highestFinalizedSlot,
 		mode:                modeStopOnFinalizedEpoch,
 	})
@@ -81,6 +91,9 @@ func (s *Service) syncToFinalizedEpoch(ctx context.Context, genesis time.Time) e
 	}
 
 	for data := range queue.fetchedData {
+		// If blobs are available. Verify blobs and blocks are consistence.
+		// We can't import a block if there's no associated blob within DA bound.
+		// The blob has to pass aggregated proof check.
 		s.processFetchedData(ctx, genesis, s.cfg.Chain.HeadSlot(), data)
 	}
 
@@ -98,10 +111,17 @@ func (s *Service) syncToFinalizedEpoch(ctx context.Context, genesis time.Time) e
 // syncToNonFinalizedEpoch sync from head to best known non-finalized epoch supported by majority
 // of peers (no less than MinimumSyncPeers*2 peers).
 func (s *Service) syncToNonFinalizedEpoch(ctx context.Context, genesis time.Time) error {
+	vr := s.clock.GenesisValidatorsRoot()
+	ctxMap, err := sync.ContextByteVersionsForValRoot(vr)
+	if err != nil {
+		return errors.Wrapf(err, "unable to initialize context version map using genesis validator root = %#x", vr)
+	}
 	queue := newBlocksQueue(ctx, &blocksQueueConfig{
 		p2p:                 s.cfg.P2P,
 		db:                  s.cfg.DB,
 		chain:               s.cfg.Chain,
+		clock:               s.clock,
+		ctxMap:              ctxMap,
 		highestExpectedSlot: slots.Since(genesis),
 		mode:                modeNonConstrained,
 	})
@@ -128,7 +148,7 @@ func (s *Service) processFetchedData(
 	defer s.updatePeerScorerStats(data.pid, startSlot)
 
 	// Use Batch Block Verify to process and verify batches directly.
-	if err := s.processBatchedBlocks(ctx, genesis, data.blocks, s.cfg.Chain.ReceiveBlockBatch); err != nil {
+	if err := s.processBatchedBlocks(ctx, genesis, data.bwb, s.cfg.Chain.ReceiveBlockBatch); err != nil {
 		log.WithError(err).Warn("Skip processing batched blocks")
 	}
 }
@@ -141,8 +161,8 @@ func (s *Service) processFetchedDataRegSync(
 	blockReceiver := s.cfg.Chain.ReceiveBlock
 	invalidBlocks := 0
 	blksWithoutParentCount := 0
-	for _, blk := range data.blocks {
-		if err := s.processBlock(ctx, genesis, blk, blockReceiver); err != nil {
+	for _, b := range data.bwb {
+		if err := s.processBlock(ctx, genesis, b, blockReceiver); err != nil {
 			switch {
 			case errors.Is(err, errBlockAlreadyProcessed):
 				log.WithError(err).Debug("Block is not processed")
@@ -158,13 +178,13 @@ func (s *Service) processFetchedDataRegSync(
 	}
 	if blksWithoutParentCount > 0 {
 		log.WithFields(logrus.Fields{
-			"missingParent": fmt.Sprintf("%#x", data.blocks[0].Block().ParentRoot()),
-			"firstSlot":     data.blocks[0].Block().Slot(),
-			"lastSlot":      data.blocks[blksWithoutParentCount-1].Block().Slot(),
+			"missingParent": fmt.Sprintf("%#x", data.bwb[0].Block.Block().ParentRoot()),
+			"firstSlot":     data.bwb[0].Block.Block().Slot(),
+			"lastSlot":      data.bwb[blksWithoutParentCount-1].Block.Block().Slot(),
 		}).Debug("Could not process batch blocks due to missing parent")
 	}
 	// Add more visible logging if all blocks cannot be processed.
-	if len(data.blocks) == invalidBlocks {
+	if len(data.bwb) == invalidBlocks {
 		log.WithField("error", "Range had no valid blocks to process").Warn("Range is not processed")
 	}
 }
@@ -204,20 +224,20 @@ func (s *Service) logSyncStatus(genesis time.Time, blk interfaces.ReadOnlyBeacon
 }
 
 // logBatchSyncStatus and increments the block processing counter.
-func (s *Service) logBatchSyncStatus(genesis time.Time, blks []interfaces.ReadOnlySignedBeaconBlock, blkRoot [32]byte) {
-	s.counter.Incr(int64(len(blks)))
+func (s *Service) logBatchSyncStatus(genesis time.Time, firstBlk blocks.ROBlock, nBlocks int) {
+	s.counter.Incr(int64(nBlocks))
 	rate := float64(s.counter.Rate()) / counterSeconds
 	if rate == 0 {
 		rate = 1
 	}
-	firstBlk := blks[0]
+	firstRoot := firstBlk.Root()
 	timeRemaining := time.Duration(float64(slots.Since(genesis)-firstBlk.Block().Slot())/rate) * time.Second
 	log.WithFields(logrus.Fields{
 		"peers":           len(s.cfg.P2P.Peers().Connected()),
 		"blocksPerSecond": fmt.Sprintf("%.1f", rate),
 	}).Infof(
 		"Processing block batch of size %d starting from  %s %d/%d - estimated time remaining %s",
-		len(blks), fmt.Sprintf("0x%s...", hex.EncodeToString(blkRoot[:])[:8]),
+		nBlocks, fmt.Sprintf("0x%s...", hex.EncodeToString(firstRoot[:])[:8]),
 		firstBlk.Block().Slot(), slots.Since(genesis), timeRemaining,
 	)
 }
@@ -226,14 +246,12 @@ func (s *Service) logBatchSyncStatus(genesis time.Time, blks []interfaces.ReadOn
 func (s *Service) processBlock(
 	ctx context.Context,
 	genesis time.Time,
-	blk interfaces.ReadOnlySignedBeaconBlock,
+	bwb blocks.BlockWithVerifiedBlobs,
 	blockReceiver blockReceiverFn,
 ) error {
-	blkRoot, err := blk.Block().HashTreeRoot()
-	if err != nil {
-		return err
-	}
-	if s.isProcessedBlock(ctx, blk, blkRoot) {
+	blk := bwb.Block
+	blkRoot := blk.Root()
+	if s.isProcessedBlock(ctx, blk) {
 		return fmt.Errorf("slot: %d , root %#x: %w", blk.Block().Slot(), blkRoot, errBlockAlreadyProcessed)
 	}
 
@@ -244,48 +262,63 @@ func (s *Service) processBlock(
 	return blockReceiver(ctx, blk, blkRoot)
 }
 
+type processedChecker func(context.Context, blocks.ROBlock) bool
+
+func validUnprocessed(ctx context.Context, bwb []blocks.BlockWithVerifiedBlobs, headSlot primitives.Slot, isProc processedChecker) ([]blocks.BlockWithVerifiedBlobs, error) {
+	// use a pointer to avoid confusing the zero-value with the case where the first element is processed.
+	var processed *int
+	for i := range bwb {
+		b := bwb[i].Block
+		if headSlot >= b.Block().Slot() && isProc(ctx, b) {
+			processed = &i
+			continue
+		}
+		if i > 0 {
+			parent := bwb[i-1].Block
+			if parent.Root() != b.Block().ParentRoot() {
+				return nil, fmt.Errorf("expected linear block list with parent root of %#x (slot %d) but received %#x (slot %d)",
+					parent, parent.Block().Slot(), b.Block().ParentRoot(), b.Block().Slot())
+			}
+		}
+	}
+	if processed == nil {
+		return bwb, nil
+	}
+	if *processed+1 == len(bwb) {
+		maxIncoming := bwb[len(bwb)-1].Block
+		maxRoot := maxIncoming.Root()
+		return nil, fmt.Errorf("headSlot:%d, blockSlot:%d , root %#x:%w", headSlot, maxIncoming.Block().Slot(), maxRoot, errBlockAlreadyProcessed)
+	}
+	return bwb[*processed:], nil
+}
+
 func (s *Service) processBatchedBlocks(ctx context.Context, genesis time.Time,
-	blks []interfaces.ReadOnlySignedBeaconBlock, bFunc batchBlockReceiverFn) error {
-	if len(blks) == 0 {
+	bwb []blocks.BlockWithVerifiedBlobs, bFunc batchBlockReceiverFn) error {
+	if len(bwb) == 0 {
 		return errors.New("0 blocks provided into method")
 	}
-	firstBlock := blks[0]
-	blkRoot, err := firstBlock.Block().HashTreeRoot()
+	headSlot := s.cfg.Chain.HeadSlot()
+	var err error
+	bwb, err = validUnprocessed(ctx, bwb, headSlot, s.isProcessedBlock)
 	if err != nil {
 		return err
 	}
-	headSlot := s.cfg.Chain.HeadSlot()
-	for headSlot >= firstBlock.Block().Slot() && s.isProcessedBlock(ctx, firstBlock, blkRoot) {
-		if len(blks) == 1 {
-			return fmt.Errorf("headSlot:%d, blockSlot:%d , root %#x:%w", headSlot, firstBlock.Block().Slot(), blkRoot, errBlockAlreadyProcessed)
+
+	first := bwb[0].Block
+	if !s.cfg.Chain.HasBlock(ctx, first.Block().ParentRoot()) {
+		return fmt.Errorf("%w: %#x (in processBatchedBlocks, slot=%d)",
+			errParentDoesNotExist, first.Block().ParentRoot(), first.Block().Slot())
+	}
+	s.logBatchSyncStatus(genesis, first, len(bwb))
+	for _, bb := range bwb {
+		if len(bb.Blobs) == 0 {
+			continue
 		}
-		blks = blks[1:]
-		firstBlock = blks[0]
-		blkRoot, err = firstBlock.Block().HashTreeRoot()
-		if err != nil {
-			return err
+		if err := s.cfg.DB.SaveBlobSidecar(ctx, bb.Blobs); err != nil {
+			return errors.Wrapf(err, "failed to save blobs for block %#x", bb.Block.Root())
 		}
 	}
-	s.logBatchSyncStatus(genesis, blks, blkRoot)
-	parentRoot := firstBlock.Block().ParentRoot()
-	if !s.cfg.Chain.HasBlock(ctx, parentRoot) {
-		return fmt.Errorf("%w: %#x (in processBatchedBlocks, slot=%d)", errParentDoesNotExist, firstBlock.Block().ParentRoot(), firstBlock.Block().Slot())
-	}
-	blockRoots := make([][32]byte, len(blks))
-	blockRoots[0] = blkRoot
-	for i := 1; i < len(blks); i++ {
-		b := blks[i]
-		if b.Block().ParentRoot() != blockRoots[i-1] {
-			return fmt.Errorf("expected linear block list with parent root of %#x but received %#x",
-				blockRoots[i-1][:], b.Block().ParentRoot())
-		}
-		blkRoot, err := b.Block().HashTreeRoot()
-		if err != nil {
-			return err
-		}
-		blockRoots[i] = blkRoot
-	}
-	return bFunc(ctx, blks, blockRoots)
+	return bFunc(ctx, blocks.BlockWithVerifiedBlobsSlice(bwb).ROBlocks())
 }
 
 // updatePeerScorerStats adjusts monitored metrics for a peer.
@@ -304,7 +337,7 @@ func (s *Service) updatePeerScorerStats(pid peer.ID, startSlot primitives.Slot)
 }
 
 // isProcessedBlock checks DB and local cache for presence of a given block, to avoid duplicates.
-func (s *Service) isProcessedBlock(ctx context.Context, blk interfaces.ReadOnlySignedBeaconBlock, blkRoot [32]byte) bool {
+func (s *Service) isProcessedBlock(ctx context.Context, blk blocks.ROBlock) bool {
 	cp := s.cfg.Chain.FinalizedCheckpt()
 	finalizedSlot, err := slots.EpochStart(cp.Epoch)
 	if err != nil {
@@ -317,7 +350,7 @@ func (s *Service) isProcessedBlock(ctx context.Context, blk interfaces.ReadOnlyS
 	}
 	// If block exists in our db and is before or equal to our current head
 	// we ignore it.
-	if s.cfg.Chain.HeadSlot() >= blk.Block().Slot() && s.cfg.Chain.HasBlock(ctx, blkRoot) {
+	if s.cfg.Chain.HeadSlot() >= blk.Block().Slot() && s.cfg.Chain.HasBlock(ctx, blk.Root()) {
 		return true
 	}
 	return false
diff --git a/beacon-chain/sync/initial-sync/round_robin_test.go b/beacon-chain/sync/initial-sync/round_robin_test.go
index 102a5ad50b..f5c7a04548 100644
--- a/beacon-chain/sync/initial-sync/round_robin_test.go
+++ b/beacon-chain/sync/initial-sync/round_robin_test.go
@@ -10,6 +10,7 @@ import (
 	mock "github.com/prysmaticlabs/prysm/v4/beacon-chain/blockchain/testing"
 	dbtest "github.com/prysmaticlabs/prysm/v4/beacon-chain/db/testing"
 	p2pt "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/testing"
+	"github.com/prysmaticlabs/prysm/v4/beacon-chain/startup"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -292,6 +293,8 @@ func TestService_roundRobinSync(t *testing.T) {
 
 			st, err := util.NewBeaconState()
 			require.NoError(t, err)
+			gt := time.Now()
+			vr := [32]byte{}
 			mc := &mock.ChainService{
 				State: st,
 				Root:  genesisRoot[:],
@@ -299,14 +302,16 @@ func TestService_roundRobinSync(t *testing.T) {
 				FinalizedCheckPoint: &eth.Checkpoint{
 					Epoch: 0,
 				},
-				Genesis:        time.Now(),
-				ValidatorsRoot: [32]byte{},
+				Genesis:        gt,
+				ValidatorsRoot: vr,
 			} // no-op mock
+			clock := startup.NewClock(gt, vr)
 			s := &Service{
 				ctx:          context.Background(),
 				cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB},
 				synced:       abool.New(),
 				chainStarted: abool.NewBool(true),
+				clock:        clock,
 			}
 			assert.NoError(t, s.roundRobinSync(makeGenesisTime(tt.currentSlot)))
 			if s.cfg.Chain.HeadSlot() < tt.currentSlot {
@@ -364,7 +369,9 @@ func TestService_processBlock(t *testing.T) {
 		// Process block normally.
 		wsb, err := blocks.NewSignedBeaconBlock(blk1)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, wsb, func(
+		rowsb, err := blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		err = s.processBlock(ctx, genesis, blocks.BlockWithVerifiedBlobs{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error {
 			assert.NoError(t, s.cfg.Chain.ReceiveBlock(ctx, block, blockRoot))
 			return nil
@@ -374,7 +381,9 @@ func TestService_processBlock(t *testing.T) {
 		// Duplicate processing should trigger error.
 		wsb, err = blocks.NewSignedBeaconBlock(blk1)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, wsb, func(
+		rowsb, err = blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		err = s.processBlock(ctx, genesis, blocks.BlockWithVerifiedBlobs{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error {
 			return nil
 		})
@@ -383,7 +392,9 @@ func TestService_processBlock(t *testing.T) {
 		// Continue normal processing, should proceed w/o errors.
 		wsb, err = blocks.NewSignedBeaconBlock(blk2)
 		require.NoError(t, err)
-		err = s.processBlock(ctx, genesis, wsb, func(
+		rowsb, err = blocks.NewROBlock(wsb)
+		require.NoError(t, err)
+		err = s.processBlock(ctx, genesis, blocks.BlockWithVerifiedBlobs{Block: rowsb}, func(
 			ctx context.Context, block interfaces.ReadOnlySignedBeaconBlock, blockRoot [32]byte) error {
 			assert.NoError(t, s.cfg.Chain.ReceiveBlock(ctx, block, blockRoot))
 			return nil
@@ -418,7 +429,7 @@ func TestService_processBlockBatch(t *testing.T) {
 	genesis := makeGenesisTime(32)
 
 	t.Run("process non-linear batch", func(t *testing.T) {
-		var batch []interfaces.ReadOnlySignedBeaconBlock
+		var batch []blocks.BlockWithVerifiedBlobs
 		currBlockRoot := genesisBlkRoot
 		for i := primitives.Slot(1); i < 10; i++ {
 			parentRoot := currBlockRoot
@@ -430,11 +441,13 @@ func TestService_processBlockBatch(t *testing.T) {
 			util.SaveBlock(t, context.Background(), beaconDB, blk1)
 			wsb, err := blocks.NewSignedBeaconBlock(blk1)
 			require.NoError(t, err)
-			batch = append(batch, wsb)
+			rowsb, err := blocks.NewROBlock(wsb)
+			require.NoError(t, err)
+			batch = append(batch, blocks.BlockWithVerifiedBlobs{Block: rowsb})
 			currBlockRoot = blk1Root
 		}
 
-		var batch2 []interfaces.ReadOnlySignedBeaconBlock
+		var batch2 []blocks.BlockWithVerifiedBlobs
 		for i := primitives.Slot(10); i < 20; i++ {
 			parentRoot := currBlockRoot
 			blk1 := util.NewBeaconBlock()
@@ -445,26 +458,29 @@ func TestService_processBlockBatch(t *testing.T) {
 			util.SaveBlock(t, context.Background(), beaconDB, blk1)
 			wsb, err := blocks.NewSignedBeaconBlock(blk1)
 			require.NoError(t, err)
-			batch2 = append(batch2, wsb)
+			rowsb, err := blocks.NewROBlock(wsb)
+			require.NoError(t, err)
+			batch2 = append(batch2, blocks.BlockWithVerifiedBlobs{Block: rowsb})
 			currBlockRoot = blk1Root
 		}
 
-		// Process block normally.
-		err = s.processBatchedBlocks(ctx, genesis, batch, func(
-			ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock, blockRoots [][32]byte) error {
-			assert.NoError(t, s.cfg.Chain.ReceiveBlockBatch(ctx, blks, blockRoots))
+		cbnormal := func(ctx context.Context, blks []blocks.ROBlock) error {
+			assert.NoError(t, s.cfg.Chain.ReceiveBlockBatch(ctx, blks))
 			return nil
-		})
+		}
+		// Process block normally.
+		err = s.processBatchedBlocks(ctx, genesis, batch, cbnormal)
 		assert.NoError(t, err)
 
-		// Duplicate processing should trigger error.
-		err = s.processBatchedBlocks(ctx, genesis, batch, func(
-			ctx context.Context, blocks []interfaces.ReadOnlySignedBeaconBlock, blockRoots [][32]byte) error {
+		cbnil := func(ctx context.Context, blocks []blocks.ROBlock) error {
 			return nil
-		})
+		}
+
+		// Duplicate processing should trigger error.
+		err = s.processBatchedBlocks(ctx, genesis, batch, cbnil)
 		assert.ErrorContains(t, "block is already processed", err)
 
-		var badBatch2 []interfaces.ReadOnlySignedBeaconBlock
+		var badBatch2 []blocks.BlockWithVerifiedBlobs
 		for i, b := range batch2 {
 			// create a non-linear batch
 			if i%3 == 0 && i != 0 {
@@ -474,19 +490,12 @@ func TestService_processBlockBatch(t *testing.T) {
 		}
 
 		// Bad batch should fail because it is non linear
-		err = s.processBatchedBlocks(ctx, genesis, badBatch2, func(
-			ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock, blockRoots [][32]byte) error {
-			return nil
-		})
+		err = s.processBatchedBlocks(ctx, genesis, badBatch2, cbnil)
 		expectedSubErr := "expected linear block list"
 		assert.ErrorContains(t, expectedSubErr, err)
 
 		// Continue normal processing, should proceed w/o errors.
-		err = s.processBatchedBlocks(ctx, genesis, batch2, func(
-			ctx context.Context, blks []interfaces.ReadOnlySignedBeaconBlock, blockRoots [][32]byte) error {
-			assert.NoError(t, s.cfg.Chain.ReceiveBlockBatch(ctx, blks, blockRoots))
-			return nil
-		})
+		err = s.processBatchedBlocks(ctx, genesis, batch2, cbnormal)
 		assert.NoError(t, err)
 		assert.Equal(t, primitives.Slot(19), s.cfg.Chain.HeadSlot(), "Unexpected head slot")
 	})
@@ -537,6 +546,8 @@ func TestService_blockProviderScoring(t *testing.T) {
 	st, err := util.NewBeaconState()
 	require.NoError(t, err)
 	require.NoError(t, err)
+	gt := time.Now()
+	vr := [32]byte{}
 	mc := &mock.ChainService{
 		State: st,
 		Root:  genesisRoot[:],
@@ -545,14 +556,16 @@ func TestService_blockProviderScoring(t *testing.T) {
 			Epoch: 0,
 			Root:  make([]byte, 32),
 		},
-		Genesis:        time.Now(),
-		ValidatorsRoot: [32]byte{},
+		Genesis:        gt,
+		ValidatorsRoot: vr,
 	} // no-op mock
+	clock := startup.NewClock(gt, vr)
 	s := &Service{
 		ctx:          context.Background(),
 		cfg:          &Config{Chain: mc, P2P: p, DB: beaconDB},
 		synced:       abool.New(),
 		chainStarted: abool.NewBool(true),
+		clock:        clock,
 	}
 	scorer := s.cfg.P2P.Peers().Scorers().BlockProviderScorer()
 	expectedBlockSlots := makeSequence(1, 160)
@@ -601,6 +614,9 @@ func TestService_syncToFinalizedEpoch(t *testing.T) {
 
 	st, err := util.NewBeaconState()
 	require.NoError(t, err)
+	gt := time.Now()
+	vr := [32]byte{}
+	clock := startup.NewClock(gt, vr)
 	mc := &mock.ChainService{
 		State: st,
 		Root:  genesisRoot[:],
@@ -609,8 +625,8 @@ func TestService_syncToFinalizedEpoch(t *testing.T) {
 			Epoch: 0,
 			Root:  make([]byte, 32),
 		},
-		Genesis:        time.Now(),
-		ValidatorsRoot: [32]byte{},
+		Genesis:        gt,
+		ValidatorsRoot: vr,
 	}
 	s := &Service{
 		ctx:          context.Background(),
@@ -618,6 +634,7 @@ func TestService_syncToFinalizedEpoch(t *testing.T) {
 		synced:       abool.New(),
 		chainStarted: abool.NewBool(true),
 		counter:      ratecounter.NewRateCounter(counterSeconds * time.Second),
+		clock:        clock,
 	}
 	expectedBlockSlots := makeSequence(1, 191)
 	currentSlot := primitives.Slot(191)
diff --git a/beacon-chain/sync/initial-sync/service.go b/beacon-chain/sync/initial-sync/service.go
index 0cc94edf64..e9d101ab3c 100644
--- a/beacon-chain/sync/initial-sync/service.go
+++ b/beacon-chain/sync/initial-sync/service.go
@@ -35,7 +35,7 @@ type blockchainService interface {
 // Config to set up the initial sync service.
 type Config struct {
 	P2P                 p2p.P2P
-	DB                  db.ReadOnlyDatabase
+	DB                  db.NoHeadAccessDatabase
 	Chain               blockchainService
 	StateNotifier       statefeed.Notifier
 	BlockNotifier       blockfeed.Notifier
diff --git a/beacon-chain/sync/rpc_blob_sidecars_by_range.go b/beacon-chain/sync/rpc_blob_sidecars_by_range.go
index 6c98967a7c..f8475bb572 100644
--- a/beacon-chain/sync/rpc_blob_sidecars_by_range.go
+++ b/beacon-chain/sync/rpc_blob_sidecars_by_range.go
@@ -2,6 +2,7 @@ package sync
 
 import (
 	"context"
+	"math"
 	"time"
 
 	libp2pcore "github.com/libp2p/go-libp2p/core"
@@ -110,7 +111,14 @@ func (s *Service) blobSidecarsByRangeRPCHandler(ctx context.Context, msg interfa
 	return nil
 }
 
-func blobsByRangeMinStartSlot(current primitives.Slot) (primitives.Slot, error) {
+// BlobsByRangeMinStartSlot returns the lowest slot that we should expect peers to respect as the
+// start slot in a BlobSidecarsByRange request. This can be used to validate incoming requests and
+// to avoid pestering peers with requests for blobs that are outside the retention window.
+func BlobsByRangeMinStartSlot(current primitives.Slot) (primitives.Slot, error) {
+	// Avoid overflow if we're running on a config where deneb is set to far future epoch.
+	if params.BeaconConfig().DenebForkEpoch == math.MaxUint64 {
+		return primitives.Slot(math.MaxUint64), nil
+	}
 	minReqEpochs := params.BeaconNetworkConfig().MinEpochsForBlobsSidecarsRequest
 	currEpoch := slots.ToEpoch(current)
 	minStart := params.BeaconConfig().DenebForkEpoch
@@ -156,9 +164,9 @@ func validateBlobsByRange(r *pb.BlobSidecarsByRangeRequest, current primitives.S
 	// [max(current_epoch - MIN_EPOCHS_FOR_BLOB_SIDECARS_REQUESTS, DENEB_FORK_EPOCH), current_epoch]
 	// where current_epoch is defined by the current wall-clock time,
 	// and clients MUST support serving requests of blobs on this range.
-	minStartSlot, err := blobsByRangeMinStartSlot(current)
+	minStartSlot, err := BlobsByRangeMinStartSlot(current)
 	if err != nil {
-		return rangeParams{}, errors.Wrap(p2ptypes.ErrInvalidRequest, "blobsByRangeMinStartSlot error")
+		return rangeParams{}, errors.Wrap(p2ptypes.ErrInvalidRequest, "BlobsByRangeMinStartSlot error")
 	}
 	if rp.start > maxStart {
 		return rangeParams{}, errors.Wrap(p2ptypes.ErrInvalidRequest, "start > maxStart")
diff --git a/beacon-chain/sync/rpc_blob_sidecars_by_range_test.go b/beacon-chain/sync/rpc_blob_sidecars_by_range_test.go
index 8a4f4386dd..5db6033c92 100644
--- a/beacon-chain/sync/rpc_blob_sidecars_by_range_test.go
+++ b/beacon-chain/sync/rpc_blob_sidecars_by_range_test.go
@@ -177,7 +177,7 @@ func TestBlobsByRangeValidation(t *testing.T) {
 		and clients MUST support serving requests of blobs on this range.
 	*/
 	defaultCurrent := denebSlot + 100 + minReqSlots
-	defaultMinStart, err := blobsByRangeMinStartSlot(defaultCurrent)
+	defaultMinStart, err := BlobsByRangeMinStartSlot(defaultCurrent)
 	require.NoError(t, err)
 	cases := []struct {
 		name    string
diff --git a/beacon-chain/sync/rpc_blob_sidecars_by_root_test.go b/beacon-chain/sync/rpc_blob_sidecars_by_root_test.go
index 93b9d5854e..edef14c9f4 100644
--- a/beacon-chain/sync/rpc_blob_sidecars_by_root_test.go
+++ b/beacon-chain/sync/rpc_blob_sidecars_by_root_test.go
@@ -130,6 +130,11 @@ func TestReadChunkEncodedBlobs(t *testing.T) {
 			nblocks:      1,
 			streamReader: readChunkEncodedBlobsAsStreamReader,
 		},
+		{
+			name:         "test peer sending excess blobs",
+			nblocks:      1,
+			streamReader: readChunkEncodedBlobsLowMax,
+		},
 	}
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
@@ -138,6 +143,20 @@ func TestReadChunkEncodedBlobs(t *testing.T) {
 	}
 }
 
+// Specifies a max expected chunk parameter of 1, so that a response with one or more blobs will give ErrInvalidFetchedData.
+func readChunkEncodedBlobsLowMax(t *testing.T, s *Service, expect []*expectedBlobChunk) func(network.Stream) {
+	encoding := s.cfg.p2p.Encoding()
+	ctxMap, err := ContextByteVersionsForValRoot(s.cfg.clock.GenesisValidatorsRoot())
+	require.NoError(t, err)
+	vf := func(sidecar *ethpb.BlobSidecar) error {
+		return nil
+	}
+	return func(stream network.Stream) {
+		_, err := readChunkEncodedBlobs(stream, encoding, ctxMap, vf, 1)
+		require.ErrorIs(t, err, ErrInvalidFetchedData)
+	}
+}
+
 func readChunkEncodedBlobsAsStreamReader(t *testing.T, s *Service, expect []*expectedBlobChunk) func(network.Stream) {
 	encoding := s.cfg.p2p.Encoding()
 	ctxMap, err := ContextByteVersionsForValRoot(s.cfg.clock.GenesisValidatorsRoot())
@@ -146,7 +165,7 @@ func readChunkEncodedBlobsAsStreamReader(t *testing.T, s *Service, expect []*exp
 		return nil
 	}
 	return func(stream network.Stream) {
-		scs, err := readChunkEncodedBlobs(stream, encoding, ctxMap, vf)
+		scs, err := readChunkEncodedBlobs(stream, encoding, ctxMap, vf, params.BeaconNetworkConfig().MaxRequestBlobSidecars)
 		require.NoError(t, err)
 		require.Equal(t, len(expect), len(scs))
 		for i, sc := range scs {
diff --git a/beacon-chain/sync/rpc_send_request.go b/beacon-chain/sync/rpc_send_request.go
index b56c184bbc..2b7ab2b248 100644
--- a/beacon-chain/sync/rpc_send_request.go
+++ b/beacon-chain/sync/rpc_send_request.go
@@ -12,6 +12,7 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p"
 	"github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/encoder"
 	p2ptypes "github.com/prysmaticlabs/prysm/v4/beacon-chain/p2p/types"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
 	"github.com/prysmaticlabs/prysm/v4/config/params"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -21,9 +22,15 @@ import (
 	"github.com/prysmaticlabs/prysm/v4/time/slots"
 )
 
-// ErrInvalidFetchedData is thrown if stream fails to provide requested blocks.
+// ErrInvalidFetchedData is used to signal that an error occurred which should result in peer downscoring.
 var ErrInvalidFetchedData = errors.New("invalid data returned from peer")
 
+var errMaxRequestBlobSidecarsExceeded = errors.Wrap(ErrInvalidFetchedData, "peer exceeded req blob chunk tx limit")
+var errBlobChunkedReadFailure = errors.New("failed to read stream of chunk-encoded blobs")
+var errBlobUnmarshal = errors.New("Could not unmarshal chunk-encoded blob")
+var errUnrequestedRoot = errors.New("Received BlobSidecar in response that was not requested")
+var errBlobResponseOutOfBounds = errors.New("received BlobSidecar with slot outside BlobSidecarsByRangeRequest bounds")
+
 // BeaconBlockProcessor defines a block processing function, which allows to start utilizing
 // blocks even before all blocks are ready.
 type BeaconBlockProcessor func(block interfaces.ReadOnlySignedBeaconBlock) error
@@ -135,8 +142,8 @@ func SendBeaconBlocksByRootRequest(
 	return blocks, nil
 }
 
-func SendBlobsByRangeRequest(ctx context.Context, ci blockchain.ForkFetcher, p2pApi p2p.SenderEncoder, pid peer.ID, ctxMap ContextByteVersions, req *pb.BlobSidecarsByRangeRequest) ([]*pb.BlobSidecar, error) {
-	topic, err := p2p.TopicFromMessage(p2p.BlobSidecarsByRangeName, slots.ToEpoch(ci.CurrentSlot()))
+func SendBlobsByRangeRequest(ctx context.Context, tor blockchain.TemporalOracle, p2pApi p2p.SenderEncoder, pid peer.ID, ctxMap ContextByteVersions, req *pb.BlobSidecarsByRangeRequest) ([]*pb.BlobSidecar, error) {
+	topic, err := p2p.TopicFromMessage(p2p.BlobSidecarsByRangeName, slots.ToEpoch(tor.CurrentSlot()))
 	if err != nil {
 		return nil, err
 	}
@@ -147,7 +154,11 @@ func SendBlobsByRangeRequest(ctx context.Context, ci blockchain.ForkFetcher, p2p
 	}
 	defer closeStream(stream, log)
 
-	return readChunkEncodedBlobs(stream, p2pApi.Encoding(), ctxMap, blobValidatorFromRangeReq(req))
+	max := params.BeaconNetworkConfig().MaxRequestBlobSidecars
+	if max > req.Count*fieldparams.MaxBlobsPerBlock {
+		max = req.Count * fieldparams.MaxBlobsPerBlock
+	}
+	return readChunkEncodedBlobs(stream, p2pApi.Encoding(), ctxMap, blobValidatorFromRangeReq(req), max)
 }
 
 func SendBlobSidecarByRoot(
@@ -169,14 +180,13 @@ func SendBlobSidecarByRoot(
 	}
 	defer closeStream(stream, log)
 
-	return readChunkEncodedBlobs(stream, p2pApi.Encoding(), ctxMap, blobValidatorFromRootReq(req))
+	max := params.BeaconNetworkConfig().MaxRequestBlobSidecars
+	if max > uint64(len(*req))*fieldparams.MaxBlobsPerBlock {
+		max = uint64(len(*req)) * fieldparams.MaxBlobsPerBlock
+	}
+	return readChunkEncodedBlobs(stream, p2pApi.Encoding(), ctxMap, blobValidatorFromRootReq(req), max)
 }
 
-var ErrBlobChunkedReadFailure = errors.New("failed to read stream of chunk-encoded blobs")
-var ErrBlobUnmarshal = errors.New("Could not unmarshal chunk-encoded blob")
-var ErrUnrequestedRoot = errors.New("Received BlobSidecar in response that was not requested")
-var ErrBlobResponseOutOfBounds = errors.New("received BlobSidecar with slot outside BlobSidecarsByRangeRequest bounds")
-
 type blobResponseValidation func(*pb.BlobSidecar) error
 
 func blobValidatorFromRootReq(req *p2ptypes.BlobSidecarsByRootReq) blobResponseValidation {
@@ -186,7 +196,7 @@ func blobValidatorFromRootReq(req *p2ptypes.BlobSidecarsByRootReq) blobResponseV
 	}
 	return func(sc *pb.BlobSidecar) error {
 		if requested := roots[bytesutil.ToBytes32(sc.BlockRoot)]; !requested {
-			return errors.Wrapf(ErrUnrequestedRoot, "root=%#x", sc.BlockRoot)
+			return errors.Wrapf(errUnrequestedRoot, "root=%#x", sc.BlockRoot)
 		}
 		return nil
 	}
@@ -196,52 +206,69 @@ func blobValidatorFromRangeReq(req *pb.BlobSidecarsByRangeRequest) blobResponseV
 	end := req.StartSlot + primitives.Slot(req.Count)
 	return func(sc *pb.BlobSidecar) error {
 		if sc.Slot < req.StartSlot || sc.Slot >= end {
-			return errors.Wrapf(ErrBlobResponseOutOfBounds, "req start,end:%d,%d, resp:%d", req.StartSlot, end, sc.Slot)
+			return errors.Wrapf(errBlobResponseOutOfBounds, "req start,end:%d,%d, resp:%d", req.StartSlot, end, sc.Slot)
 		}
 		return nil
 	}
 }
 
-func readChunkEncodedBlobs(stream network.Stream, encoding encoder.NetworkEncoding, ctxMap ContextByteVersions, vf blobResponseValidation) ([]*pb.BlobSidecar, error) {
-	decode := encoding.DecodeWithMaxLength
-	max := int(params.BeaconNetworkConfig().MaxRequestBlobSidecars)
-	var (
-		code uint8
-		msg  string
-		err  error
-	)
+func readChunkEncodedBlobs(stream network.Stream, encoding encoder.NetworkEncoding, ctxMap ContextByteVersions, vf blobResponseValidation, max uint64) ([]*pb.BlobSidecar, error) {
 	sidecars := make([]*pb.BlobSidecar, 0)
-	for i := 0; i < max; i++ {
-		code, msg, err = ReadStatusCode(stream, encoding)
+	// Attempt an extra read beyond max to check if the peer is violating the spec by
+	// sending more than MAX_REQUEST_BLOB_SIDECARS, or more blobs than requested.
+	for i := uint64(0); i < max+1; i++ {
+		sc, err := readChunkedBlobSidecar(stream, encoding, ctxMap, vf)
 		if err != nil {
-			break
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return nil, err
 		}
-		if code != 0 {
-			return nil, errors.Wrap(ErrBlobChunkedReadFailure, msg)
-		}
-		ctxb, err := readContextFromStream(stream)
-		if err != nil {
-			return nil, errors.Wrap(err, "error reading chunk context bytes from stream")
-		}
-
-		v, found := ctxMap[bytesutil.ToBytes4(ctxb)]
-		if !found {
-			return nil, errors.Wrapf(ErrBlobUnmarshal, fmt.Sprintf("unrecognized fork digest %#x", ctxb))
-		}
-		if v != version.Deneb {
-			return nil, fmt.Errorf("unexpected context bytes for deneb BlobSidecar, ctx=%#x, v=%s", ctxb, version.String(v))
-		}
-		sc := &pb.BlobSidecar{}
-		if err := decode(stream, sc); err != nil {
-			return nil, errors.Wrap(err, "failed to decode the protobuf-encoded BlobSidecar message from RPC chunk stream")
-		}
-		if err := vf(sc); err != nil {
-			return nil, errors.Wrap(err, "validation failure decoding blob RPC response")
+		if i == max {
+			// We have read an extra sidecar beyond what the spec allows. Since this is a spec violation, we return
+			// an error that wraps ErrInvalidFetchedData. The part of the state machine that handles rpc peer scoring
+			// will downscore the peer if the request ends in an error that wraps that one.
+			return nil, errMaxRequestBlobSidecarsExceeded
 		}
 		sidecars = append(sidecars, sc)
 	}
-	if !errors.Is(err, io.EOF) {
-		return nil, err
-	}
+
 	return sidecars, nil
 }
+
+func readChunkedBlobSidecar(stream network.Stream, encoding encoder.NetworkEncoding, ctxMap ContextByteVersions, vf blobResponseValidation) (*pb.BlobSidecar, error) {
+	decode := encoding.DecodeWithMaxLength
+	var (
+		code uint8
+		msg  string
+	)
+	code, msg, err := ReadStatusCode(stream, encoding)
+	if err != nil {
+		return nil, err
+	}
+	if code != 0 {
+		return nil, errors.Wrap(errBlobChunkedReadFailure, msg)
+	}
+	ctxb, err := readContextFromStream(stream)
+	if err != nil {
+		return nil, errors.Wrap(err, "error reading chunk context bytes from stream")
+	}
+
+	v, found := ctxMap[bytesutil.ToBytes4(ctxb)]
+	if !found {
+		return nil, errors.Wrapf(errBlobUnmarshal, fmt.Sprintf("unrecognized fork digest %#x", ctxb))
+	}
+	// Only deneb is supported at this time, because we lack a fork-spanning interface/union type for blobs.
+	if v != version.Deneb {
+		return nil, fmt.Errorf("unexpected context bytes for deneb BlobSidecar, ctx=%#x, v=%s", ctxb, version.String(v))
+	}
+	sc := &pb.BlobSidecar{}
+	if err := decode(stream, sc); err != nil {
+		return nil, errors.Wrap(err, "failed to decode the protobuf-encoded BlobSidecar message from RPC chunk stream")
+	}
+	if err := vf(sc); err != nil {
+		return nil, errors.Wrap(err, "validation failure decoding blob RPC response")
+	}
+
+	return sc, nil
+}
diff --git a/beacon-chain/sync/rpc_send_request_test.go b/beacon-chain/sync/rpc_send_request_test.go
index ca4aadb6f3..36d9fb35ab 100644
--- a/beacon-chain/sync/rpc_send_request_test.go
+++ b/beacon-chain/sync/rpc_send_request_test.go
@@ -495,7 +495,7 @@ func TestBlobValidatorFromRootReq(t *testing.T) {
 			name:     "invalid",
 			ids:      []*ethpb.BlobIdentifier{{BlockRoot: validRoot}},
 			response: []*ethpb.BlobSidecar{{BlockRoot: invalidRoot}},
-			err:      ErrUnrequestedRoot,
+			err:      errUnrequestedRoot,
 		},
 	}
 	for _, c := range cases {
@@ -544,7 +544,7 @@ func TestBlobValidatorFromRangeReq(t *testing.T) {
 				Count:     1,
 			},
 			response: []*ethpb.BlobSidecar{{Slot: 9}},
-			err:      ErrBlobResponseOutOfBounds,
+			err:      errBlobResponseOutOfBounds,
 		},
 		{
 			name: "invalid - after, count 1",
@@ -553,7 +553,7 @@ func TestBlobValidatorFromRangeReq(t *testing.T) {
 				Count:     1,
 			},
 			response: []*ethpb.BlobSidecar{{Slot: 11}},
-			err:      ErrBlobResponseOutOfBounds,
+			err:      errBlobResponseOutOfBounds,
 		},
 		{
 			name: "invalid - after, multi",
@@ -562,7 +562,7 @@ func TestBlobValidatorFromRangeReq(t *testing.T) {
 				Count:     10,
 			},
 			response: []*ethpb.BlobSidecar{{Slot: 23}},
-			err:      ErrBlobResponseOutOfBounds,
+			err:      errBlobResponseOutOfBounds,
 		},
 		{
 			name: "invalid - after, at boundary, multi",
@@ -571,7 +571,7 @@ func TestBlobValidatorFromRangeReq(t *testing.T) {
 				Count:     10,
 			},
 			response: []*ethpb.BlobSidecar{{Slot: 20}},
-			err:      ErrBlobResponseOutOfBounds,
+			err:      errBlobResponseOutOfBounds,
 		},
 	}
 	for _, c := range cases {
diff --git a/consensus-types/blocks/roblock.go b/consensus-types/blocks/roblock.go
index d63d948631..11f5292761 100644
--- a/consensus-types/blocks/roblock.go
+++ b/consensus-types/blocks/roblock.go
@@ -5,6 +5,7 @@ import (
 	"sort"
 
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/interfaces"
+	eth "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
 )
 
 // ROBlock is a value that embeds a ReadOnlySignedBeaconBlock along with its block root ([32]byte).
@@ -73,3 +74,44 @@ func (s ROBlockSlice) Swap(i, j int) {
 func (s ROBlockSlice) Len() int {
 	return len(s)
 }
+
+type BlockWithVerifiedBlobs struct {
+	Block ROBlock
+	Blobs []*eth.BlobSidecar
+}
+
+type BlockWithVerifiedBlobsSlice []BlockWithVerifiedBlobs
+
+func (s BlockWithVerifiedBlobsSlice) ROBlocks() []ROBlock {
+	r := make([]ROBlock, len(s))
+	for i := range s {
+		r[i] = s[i].Block
+	}
+	return r
+}
+
+// Less reports whether the element with index i must sort before the element with index j.
+// ROBlocks are ordered first by their slot,
+// with a lexicographic sort of roots breaking ties for slots with duplicate blocks.
+func (s BlockWithVerifiedBlobsSlice) Less(i, j int) bool {
+	si, sj := s[i].Block.Block().Slot(), s[j].Block.Block().Slot()
+
+	// lower slot wins
+	if si != sj {
+		return si < sj
+	}
+
+	// break slot tie lexicographically comparing roots byte for byte
+	ri, rj := s[i].Block.Root(), s[j].Block.Root()
+	return bytes.Compare(ri[:], rj[:]) < 0
+}
+
+// Swap swaps the elements with indexes i and j.
+func (s BlockWithVerifiedBlobsSlice) Swap(i, j int) {
+	s[i], s[j] = s[j], s[i]
+}
+
+// Len is the number of elements in the collection.
+func (s BlockWithVerifiedBlobsSlice) Len() int {
+	return len(s)
+}
diff --git a/testing/util/BUILD.bazel b/testing/util/BUILD.bazel
index 553926ffc7..d5bd7b1406 100644
--- a/testing/util/BUILD.bazel
+++ b/testing/util/BUILD.bazel
@@ -13,6 +13,7 @@ go_library(
         "block.go",
         "capella_block.go",
         "capella_state.go",
+        "deneb.go",
         "deneb_state.go",
         "deposits.go",
         "helpers.go",
@@ -55,7 +56,9 @@ go_library(
         "//testing/assertions:go_default_library",
         "//testing/require:go_default_library",
         "//time/slots:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//core/types:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
diff --git a/testing/util/deneb.go b/testing/util/deneb.go
new file mode 100644
index 0000000000..b9a23c1db6
--- /dev/null
+++ b/testing/util/deneb.go
@@ -0,0 +1,113 @@
+package util
+
+import (
+	"encoding/binary"
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	gethTypes "github.com/ethereum/go-ethereum/core/types"
+	fieldparams "github.com/prysmaticlabs/prysm/v4/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/blocks"
+	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
+	"github.com/prysmaticlabs/prysm/v4/encoding/bytesutil"
+	enginev1 "github.com/prysmaticlabs/prysm/v4/proto/engine/v1"
+	ethpb "github.com/prysmaticlabs/prysm/v4/proto/prysm/v1alpha1"
+	"github.com/prysmaticlabs/prysm/v4/testing/require"
+)
+
+func GenerateTestDenebBlockWithSidecar(t *testing.T, parent [32]byte, slot primitives.Slot, nblobs int) (blocks.ROBlock, []*ethpb.BlobSidecar) {
+	// Start service with 160 as allowed blocks capacity (and almost zero capacity recovery).
+	stateRoot := bytesutil.PadTo([]byte("stateRoot"), fieldparams.RootLength)
+	receiptsRoot := bytesutil.PadTo([]byte("receiptsRoot"), fieldparams.RootLength)
+	logsBloom := bytesutil.PadTo([]byte("logs"), fieldparams.LogsBloomLength)
+	parentHash := bytesutil.PadTo([]byte("parentHash"), fieldparams.RootLength)
+	tx := gethTypes.NewTransaction(
+		0,
+		common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87"),
+		big.NewInt(0), 0, big.NewInt(0),
+		nil,
+	)
+	txs := []*gethTypes.Transaction{tx}
+	encodedBinaryTxs := make([][]byte, 1)
+	var err error
+	encodedBinaryTxs[0], err = txs[0].MarshalBinary()
+	require.NoError(t, err)
+	blockHash := bytesutil.ToBytes32([]byte("foo"))
+	payload := &enginev1.ExecutionPayloadDeneb{
+		ParentHash:    parentHash,
+		FeeRecipient:  make([]byte, fieldparams.FeeRecipientLength),
+		StateRoot:     stateRoot,
+		ReceiptsRoot:  receiptsRoot,
+		LogsBloom:     logsBloom,
+		PrevRandao:    blockHash[:],
+		BlockNumber:   0,
+		GasLimit:      0,
+		GasUsed:       0,
+		Timestamp:     0,
+		ExtraData:     make([]byte, 0),
+		BaseFeePerGas: bytesutil.PadTo([]byte("baseFeePerGas"), fieldparams.RootLength),
+		ExcessDataGas: 0,
+		BlockHash:     blockHash[:],
+		Transactions:  encodedBinaryTxs,
+	}
+	block := NewBeaconBlockDeneb()
+	block.Block.Body.ExecutionPayload = payload
+	block.Block.Slot = slot
+	block.Block.ParentRoot = parent[:]
+	commitments := make([][48]byte, nblobs)
+	block.Block.Body.BlobKzgCommitments = make([][]byte, nblobs)
+	for i := range commitments {
+		binary.LittleEndian.PutUint16(commitments[i][0:16], uint16(i))
+		binary.LittleEndian.PutUint16(commitments[i][16:32], uint16(slot))
+		block.Block.Body.BlobKzgCommitments[i] = commitments[i][:]
+	}
+
+	root, err := block.Block.HashTreeRoot()
+	require.NoError(t, err)
+
+	sidecars := make([]*ethpb.BlobSidecar, len(commitments))
+	for i, c := range block.Block.Body.BlobKzgCommitments {
+		sidecars[i] = GenerateTestDenebBlobSidecar(root, block, i, c)
+	}
+
+	sbb, err := blocks.NewSignedBeaconBlock(block)
+	require.NoError(t, err)
+	rob, err := blocks.NewROBlock(sbb)
+	require.NoError(t, err)
+	return rob, sidecars
+}
+
+func GenerateTestDenebBlobSidecar(root [32]byte, block *ethpb.SignedBeaconBlockDeneb, index int, commitment []byte) *ethpb.BlobSidecar {
+	blob := make([]byte, fieldparams.BlobSize)
+	binary.LittleEndian.PutUint64(blob, uint64(index))
+	sc := &ethpb.BlobSidecar{
+		BlockRoot:       root[:],
+		Index:           uint64(index),
+		Slot:            block.Block.Slot,
+		BlockParentRoot: block.Block.ParentRoot,
+		ProposerIndex:   block.Block.ProposerIndex,
+		Blob:            blob,
+		KzgCommitment:   commitment,
+		KzgProof:        commitment,
+	}
+	return sc
+}
+
+func ExtendBlocksPlusBlobs(t *testing.T, blks []blocks.ROBlock, size int) ([]blocks.ROBlock, []*ethpb.BlobSidecar) {
+	blobs := make([]*ethpb.BlobSidecar, 0)
+	if len(blks) == 0 {
+		blk, blb := GenerateTestDenebBlockWithSidecar(t, [32]byte{}, 0, 6)
+		blobs = append(blobs, blb...)
+		blks = append(blks, blk)
+	}
+
+	for i := 0; i < size; i++ {
+		prev := blks[len(blks)-1]
+		blk, blb := GenerateTestDenebBlockWithSidecar(t, prev.Root(), prev.Block().Slot()+1, 6)
+		blobs = append(blobs, blb...)
+		blks = append(blks, blk)
+	}
+
+	return blks, blobs
+}