diff --git a/beacon-chain/blockchain/chain_info_test.go b/beacon-chain/blockchain/chain_info_test.go
index b233de3d2c..9c7189727c 100644
--- a/beacon-chain/blockchain/chain_info_test.go
+++ b/beacon-chain/blockchain/chain_info_test.go
@@ -127,7 +127,7 @@ func TestHeadSlot_CanRetrieve(t *testing.T) {
 	require.NoError(t, err)
 	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
 	require.NoError(t, err)
-	b.Block().SetSlot(100)
+	b.SetSlot(100)
 	c.head = &head{block: b, state: s}
 	assert.Equal(t, primitives.Slot(100), c.HeadSlot())
 }
diff --git a/beacon-chain/blockchain/pow_block_test.go b/beacon-chain/blockchain/pow_block_test.go
index e9ee361869..25508cd64a 100644
--- a/beacon-chain/blockchain/pow_block_test.go
+++ b/beacon-chain/blockchain/pow_block_test.go
@@ -249,7 +249,7 @@ func Test_validateTerminalBlockHash(t *testing.T) {
 	require.NoError(t, err)
 	blk, err := blocks.NewSignedBeaconBlock(util.HydrateSignedBeaconBlockBellatrix(&ethpb.SignedBeaconBlockBellatrix{}))
 	require.NoError(t, err)
-	blk.Block().SetSlot(1)
-	require.NoError(t, blk.Block().Body().SetExecution(wrapped))
+	blk.SetSlot(1)
+	require.NoError(t, blk.SetExecution(wrapped))
 	require.NoError(t, service.validateMergeBlock(ctx, blk))
 }
diff --git a/beacon-chain/execution/engine_client.go b/beacon-chain/execution/engine_client.go
index 7b6033c3b3..50028fd209 100644
--- a/beacon-chain/execution/engine_client.go
+++ b/beacon-chain/execution/engine_client.go
@@ -65,10 +65,10 @@ type ForkchoiceUpdatedResponse struct {
 type ExecutionPayloadReconstructor interface {
 	ReconstructFullBlock(
 		ctx context.Context, blindedBlock interfaces.SignedBeaconBlock,
-	) (interfaces.SignedBeaconBlock, error)
+	) (interfaces.SignedBeaconBlockWriteable, error)
 	ReconstructFullBellatrixBlockBatch(
 		ctx context.Context, blindedBlocks []interfaces.SignedBeaconBlock,
-	) ([]interfaces.SignedBeaconBlock, error)
+	) ([]interfaces.SignedBeaconBlockWriteable, error)
 }
 
 // EngineCaller defines a client that can interact with an Ethereum
@@ -443,7 +443,7 @@ func (s *Service) HeaderByNumber(ctx context.Context, number *big.Int) (*types.H
 // a beacon block with a full execution payload via the engine API.
 func (s *Service) ReconstructFullBlock(
 	ctx context.Context, blindedBlock interfaces.SignedBeaconBlock,
-) (interfaces.SignedBeaconBlock, error) {
+) (interfaces.SignedBeaconBlockWriteable, error) {
 	if err := blocks.BeaconBlockIsNil(blindedBlock); err != nil {
 		return nil, errors.Wrap(err, "cannot reconstruct bellatrix block from nil data")
 	}
@@ -494,9 +494,9 @@ func (s *Service) ReconstructFullBlock(
 // them with a full execution payload for each block via the engine API.
 func (s *Service) ReconstructFullBellatrixBlockBatch(
 	ctx context.Context, blindedBlocks []interfaces.SignedBeaconBlock,
-) ([]interfaces.SignedBeaconBlock, error) {
+) ([]interfaces.SignedBeaconBlockWriteable, error) {
 	if len(blindedBlocks) == 0 {
-		return []interfaces.SignedBeaconBlock{}, nil
+		return []interfaces.SignedBeaconBlockWriteable{}, nil
 	}
 	executionHashes := []common.Hash{}
 	validExecPayloads := []int{}
@@ -532,6 +532,7 @@ func (s *Service) ReconstructFullBellatrixBlockBatch(
 
 	// For each valid payload, we reconstruct the full block from it with the
 	// blinded block.
+	fullBlocks := make([]interfaces.SignedBeaconBlockWriteable, len(blindedBlocks))
 	for sliceIdx, realIdx := range validExecPayloads {
 		b := execBlocks[sliceIdx]
 		if b == nil {
@@ -549,7 +550,7 @@ func (s *Service) ReconstructFullBellatrixBlockBatch(
 		if err != nil {
 			return nil, err
 		}
-		blindedBlocks[realIdx] = fullBlock
+		fullBlocks[realIdx] = fullBlock
 	}
 	// For blocks that are pre-merge we simply reconstruct them via an empty
 	// execution payload.
@@ -559,10 +560,10 @@ func (s *Service) ReconstructFullBellatrixBlockBatch(
 		if err != nil {
 			return nil, err
 		}
-		blindedBlocks[realIdx] = fullBlock
+		fullBlocks[realIdx] = fullBlock
 	}
 	reconstructedExecutionPayloadCount.Add(float64(len(blindedBlocks)))
-	return blindedBlocks, nil
+	return fullBlocks, nil
 }
 
 func fullPayloadFromExecutionBlock(
diff --git a/beacon-chain/execution/engine_client_test.go b/beacon-chain/execution/engine_client_test.go
index dc1732f0af..3fd12050f9 100644
--- a/beacon-chain/execution/engine_client_test.go
+++ b/beacon-chain/execution/engine_client_test.go
@@ -769,7 +769,7 @@ func TestReconstructFullBellatrixBlockBatch(t *testing.T) {
 		require.NoError(t, err)
 		reconstructed, err := service.ReconstructFullBellatrixBlockBatch(ctx, []interfaces.SignedBeaconBlock{wrapped})
 		require.NoError(t, err)
-		require.DeepEqual(t, []interfaces.SignedBeaconBlock{wantedWrapped}, reconstructed)
+		require.DeepEqual(t, []interfaces.SignedBeaconBlockWriteable{wantedWrapped}, reconstructed)
 	})
 	t.Run("properly reconstructs block batch with correct payload", func(t *testing.T) {
 		fix := fixtures()
diff --git a/beacon-chain/execution/testing/mock_engine_client.go b/beacon-chain/execution/testing/mock_engine_client.go
index 2fcb2604ee..4051bf2f57 100644
--- a/beacon-chain/execution/testing/mock_engine_client.go
+++ b/beacon-chain/execution/testing/mock_engine_client.go
@@ -89,7 +89,7 @@ func (e *EngineClient) ExecutionBlockByHash(_ context.Context, h common.Hash, _
 // ReconstructFullBlock --
 func (e *EngineClient) ReconstructFullBlock(
 	_ context.Context, blindedBlock interfaces.SignedBeaconBlock,
-) (interfaces.SignedBeaconBlock, error) {
+) (interfaces.SignedBeaconBlockWriteable, error) {
 	if !blindedBlock.Block().IsBlinded() {
 		return nil, errors.New("block must be blinded")
 	}
@@ -108,8 +108,8 @@ func (e *EngineClient) ReconstructFullBlock(
 // ReconstructFullBellatrixBlockBatch --
 func (e *EngineClient) ReconstructFullBellatrixBlockBatch(
 	ctx context.Context, blindedBlocks []interfaces.SignedBeaconBlock,
-) ([]interfaces.SignedBeaconBlock, error) {
-	fullBlocks := make([]interfaces.SignedBeaconBlock, 0, len(blindedBlocks))
+) ([]interfaces.SignedBeaconBlockWriteable, error) {
+	fullBlocks := make([]interfaces.SignedBeaconBlockWriteable, 0, len(blindedBlocks))
 	for _, b := range blindedBlocks {
 		newBlock, err := e.ReconstructFullBlock(ctx, b)
 		if err != nil {
diff --git a/beacon-chain/rpc/prysm/v1alpha1/beacon/validators_test.go b/beacon-chain/rpc/prysm/v1alpha1/beacon/validators_test.go
index 4bd36876dd..29a9147a9f 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/beacon/validators_test.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/beacon/validators_test.go
@@ -1724,7 +1724,7 @@ func TestServer_GetValidatorParticipation_CurrentAndPrevEpochWithBits(t *testing
 	})
 }
 
-func runGetValidatorParticipationCurrentAndPrevEpoch(t *testing.T, genState state.BeaconState, gb interfaces.SignedBeaconBlock) {
+func runGetValidatorParticipationCurrentAndPrevEpoch(t *testing.T, genState state.BeaconState, gb interfaces.SignedBeaconBlockWriteable) {
 	helpers.ClearCache()
 	beaconDB := dbTest.SetupDB(t)
 
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go
index 92f0ba57c6..f1116d76fb 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer.go
@@ -71,12 +71,11 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 		return nil, status.Errorf(codes.Internal, "Could not process slots up to %d: %v", req.Slot, err)
 	}
 
-	blk := sBlk.Block()
 	// Set slot, graffiti, randao reveal, and parent root.
-	blk.SetSlot(req.Slot)
-	blk.Body().SetGraffiti(req.Graffiti)
-	blk.Body().SetRandaoReveal(req.RandaoReveal)
-	blk.SetParentRoot(parentRoot)
+	sBlk.SetSlot(req.Slot)
+	sBlk.SetGraffiti(req.Graffiti)
+	sBlk.SetRandaoReveal(req.RandaoReveal)
+	sBlk.SetParentRoot(parentRoot)
 
 	// Set eth1 data.
 	eth1Data, err := vs.eth1DataMajorityVote(ctx, head)
@@ -84,62 +83,62 @@ func (vs *Server) GetBeaconBlock(ctx context.Context, req *ethpb.BlockRequest) (
 		eth1Data = &ethpb.Eth1Data{DepositRoot: params.BeaconConfig().ZeroHash[:], BlockHash: params.BeaconConfig().ZeroHash[:]}
 		log.WithError(err).Error("Could not get eth1data")
 	}
-	blk.Body().SetEth1Data(eth1Data)
+	sBlk.SetEth1Data(eth1Data)
 
 	// Set deposit and attestation.
 	deposits, atts, err := vs.packDepositsAndAttestations(ctx, head, eth1Data) // TODO: split attestations and deposits
 	if err != nil {
-		blk.Body().SetDeposits([]*ethpb.Deposit{})
-		blk.Body().SetAttestations([]*ethpb.Attestation{})
+		sBlk.SetDeposits([]*ethpb.Deposit{})
+		sBlk.SetAttestations([]*ethpb.Attestation{})
 		log.WithError(err).Error("Could not pack deposits and attestations")
 	}
-	blk.Body().SetDeposits(deposits)
-	blk.Body().SetAttestations(atts)
+	sBlk.SetDeposits(deposits)
+	sBlk.SetAttestations(atts)
 
 	// Set proposer index.
 	idx, err := helpers.BeaconProposerIndex(ctx, head)
 	if err != nil {
 		return nil, fmt.Errorf("could not calculate proposer index %v", err)
 	}
-	blk.SetProposerIndex(idx)
+	sBlk.SetProposerIndex(idx)
 
 	// Set slashings.
 	validProposerSlashings, validAttSlashings := vs.getSlashings(ctx, head)
-	blk.Body().SetProposerSlashings(validProposerSlashings)
-	blk.Body().SetAttesterSlashings(validAttSlashings)
+	sBlk.SetProposerSlashings(validProposerSlashings)
+	sBlk.SetAttesterSlashings(validAttSlashings)
 
 	// Set exits.
-	blk.Body().SetVoluntaryExits(vs.getExits(head, req.Slot))
+	sBlk.SetVoluntaryExits(vs.getExits(head, req.Slot))
 
 	// Set sync aggregate. New in Altair.
-	vs.setSyncAggregate(ctx, blk)
+	vs.setSyncAggregate(ctx, sBlk)
 
 	// Set execution data. New in Bellatrix.
-	if err := vs.setExecutionData(ctx, blk, head); err != nil {
+	if err := vs.setExecutionData(ctx, sBlk, head); err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not set execution data: %v", err)
 	}
 
 	// Set bls to execution change. New in Capella.
-	vs.setBlsToExecData(blk, head)
+	vs.setBlsToExecData(sBlk, head)
 
 	sr, err := vs.computeStateRoot(ctx, sBlk)
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not compute state root: %v", err)
 	}
-	blk.SetStateRoot(sr)
+	sBlk.SetStateRoot(sr)
 
-	pb, err := blk.Proto()
+	pb, err := sBlk.Block().Proto()
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not convert block to proto: %v", err)
 	}
 	if slots.ToEpoch(req.Slot) >= params.BeaconConfig().CapellaForkEpoch {
-		if blk.IsBlinded() {
+		if sBlk.IsBlinded() {
 			return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_BlindedCapella{BlindedCapella: pb.(*ethpb.BlindedBeaconBlockCapella)}}, nil
 		}
 		return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_Capella{Capella: pb.(*ethpb.BeaconBlockCapella)}}, nil
 	}
 	if slots.ToEpoch(req.Slot) >= params.BeaconConfig().BellatrixForkEpoch {
-		if blk.IsBlinded() {
+		if sBlk.IsBlinded() {
 			return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_BlindedBellatrix{BlindedBellatrix: pb.(*ethpb.BlindedBeaconBlockBellatrix)}}, nil
 		}
 		return &ethpb.GenericBeaconBlock{Block: &ethpb.GenericBeaconBlock_Bellatrix{Bellatrix: pb.(*ethpb.BeaconBlockBellatrix)}}, nil
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair.go
index a622329fbd..af96047a2b 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair.go
@@ -15,12 +15,12 @@ import (
 	"go.opencensus.io/trace"
 )
 
-func (vs *Server) setSyncAggregate(ctx context.Context, blk interfaces.BeaconBlock) {
+func (vs *Server) setSyncAggregate(ctx context.Context, blk interfaces.SignedBeaconBlockWriteable) {
 	if blk.Version() < version.Altair {
 		return
 	}
 
-	syncAggregate, err := vs.getSyncAggregate(ctx, blk.Slot()-1, blk.ParentRoot())
+	syncAggregate, err := vs.getSyncAggregate(ctx, blk.Block().Slot()-1, blk.Block().ParentRoot())
 	if err != nil {
 		log.WithError(err).Error("Could not get sync aggregate")
 		emptySig := [96]byte{0xC0}
@@ -28,14 +28,14 @@ func (vs *Server) setSyncAggregate(ctx context.Context, blk interfaces.BeaconBlo
 			SyncCommitteeBits:      make([]byte, params.BeaconConfig().SyncCommitteeSize),
 			SyncCommitteeSignature: emptySig[:],
 		}
-		if err := blk.Body().SetSyncAggregate(emptyAggregate); err != nil {
+		if err := blk.SetSyncAggregate(emptyAggregate); err != nil {
 			log.WithError(err).Error("Could not set sync aggregate")
 		}
 		return
 	}
 
 	// Can not error. We already filter block versioning at the top. Phase 0 is impossible.
-	if err := blk.Body().SetSyncAggregate(syncAggregate); err != nil {
+	if err := blk.SetSyncAggregate(syncAggregate); err != nil {
 		log.WithError(err).Error("Could not set sync aggregate")
 	}
 }
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair_test.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair_test.go
index 32b5429d21..e5fd7a0b8b 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair_test.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_altair_test.go
@@ -12,11 +12,11 @@ import (
 )
 
 func TestServer_SetSyncAggregate_EmptyCase(t *testing.T) {
-	b, err := blocks.NewBeaconBlock(util.NewBeaconBlockAltair().Block)
+	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlockAltair())
 	require.NoError(t, err)
 	s := &Server{} // Sever is not initialized with sync committee pool.
 	s.setSyncAggregate(context.Background(), b)
-	agg, err := b.Body().SyncAggregate()
+	agg, err := b.Block().Body().SyncAggregate()
 	require.NoError(t, err)
 
 	emptySig := [96]byte{0xC0}
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go
index 671c1d31c1..d7d19f5bbd 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_bellatrix.go
@@ -37,9 +37,9 @@ var builderGetPayloadMissCount = promauto.NewCounter(prometheus.CounterOpts{
 const blockBuilderTimeout = 1 * time.Second
 
 // Sets the execution data for the block. Execution data can come from local EL client or remote builder depends on validator registration and circuit breaker conditions.
-func (vs *Server) setExecutionData(ctx context.Context, blk interfaces.BeaconBlock, headState state.BeaconState) error {
-	idx := blk.ProposerIndex()
-	slot := blk.Slot()
+func (vs *Server) setExecutionData(ctx context.Context, blk interfaces.SignedBeaconBlockWriteable, headState state.BeaconState) error {
+	idx := blk.Block().ProposerIndex()
+	slot := blk.Block().Slot()
 	if slots.ToEpoch(slot) < params.BeaconConfig().BellatrixForkEpoch {
 		return nil
 	}
@@ -54,18 +54,18 @@ func (vs *Server) setExecutionData(ctx context.Context, blk interfaces.BeaconBlo
 			log.WithError(err).Warn("Proposer: failed to get payload header from builder")
 		} else {
 			blk.SetBlinded(true)
-			if err := blk.Body().SetExecution(h); err != nil {
+			if err := blk.SetExecution(h); err != nil {
 				log.WithError(err).Warn("Proposer: failed to set execution payload")
 			} else {
 				return nil
 			}
 		}
 	}
-	executionData, err := vs.getExecutionPayload(ctx, slot, idx, blk.ParentRoot(), headState)
+	executionData, err := vs.getExecutionPayload(ctx, slot, idx, blk.Block().ParentRoot(), headState)
 	if err != nil {
 		return errors.Wrap(err, "failed to get execution payload")
 	}
-	return blk.Body().SetExecution(executionData)
+	return blk.SetExecution(executionData)
 }
 
 // This function retrieves the payload header given the slot number and the validator index.
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_capella.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_capella.go
index 9e3aaef125..43df4443b6 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_capella.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_capella.go
@@ -15,11 +15,11 @@ import (
 )
 
 // Sets the bls to exec data for a block.
-func (vs *Server) setBlsToExecData(blk interfaces.BeaconBlock, headState state.BeaconState) {
+func (vs *Server) setBlsToExecData(blk interfaces.SignedBeaconBlockWriteable, headState state.BeaconState) {
 	if blk.Version() < version.Capella {
 		return
 	}
-	if err := blk.Body().SetBLSToExecutionChanges([]*ethpb.SignedBLSToExecutionChange{}); err != nil {
+	if err := blk.SetBLSToExecutionChanges([]*ethpb.SignedBLSToExecutionChange{}); err != nil {
 		log.WithError(err).Error("Could not set bls to execution data in block")
 		return
 	}
@@ -28,7 +28,7 @@ func (vs *Server) setBlsToExecData(blk interfaces.BeaconBlock, headState state.B
 		log.WithError(err).Error("Could not get bls to execution changes")
 		return
 	} else {
-		if err := blk.Body().SetBLSToExecutionChanges(changes); err != nil {
+		if err := blk.SetBLSToExecutionChanges(changes); err != nil {
 			log.WithError(err).Error("Could not set bls to execution changes")
 			return
 		}
diff --git a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_empty_block.go b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_empty_block.go
index 1629302317..f59ca5d406 100644
--- a/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_empty_block.go
+++ b/beacon-chain/rpc/prysm/v1alpha1/validator/proposer_empty_block.go
@@ -11,8 +11,8 @@ import (
 	"google.golang.org/grpc/status"
 )
 
-func getEmptyBlock(slot primitives.Slot) (interfaces.SignedBeaconBlock, error) {
-	var sBlk interfaces.SignedBeaconBlock
+func getEmptyBlock(slot primitives.Slot) (interfaces.SignedBeaconBlockWriteable, error) {
+	var sBlk interfaces.SignedBeaconBlockWriteable
 	var err error
 	switch {
 	case slots.ToEpoch(slot) < params.BeaconConfig().AltairForkEpoch:
diff --git a/beacon-chain/sync/rpc_beacon_blocks_by_range.go b/beacon-chain/sync/rpc_beacon_blocks_by_range.go
index 3e4fbee807..394a886d1f 100644
--- a/beacon-chain/sync/rpc_beacon_blocks_by_range.go
+++ b/beacon-chain/sync/rpc_beacon_blocks_by_range.go
@@ -174,20 +174,39 @@ func (s *Service) writeBlockRangeToStream(ctx context.Context, startSlot, endSlo
 			break
 		}
 	}
+
+	var reconstructedBlock []interfaces.SignedBeaconBlockWriteable
 	if blindedExists {
-		reconstructedBlks, err := s.cfg.executionPayloadReconstructor.ReconstructFullBellatrixBlockBatch(ctx, blks[blindedIndex:])
+		reconstructedBlock, err = s.cfg.executionPayloadReconstructor.ReconstructFullBellatrixBlockBatch(ctx, blks[blindedIndex:])
 		if err != nil {
 			log.WithError(err).Error("Could not reconstruct full bellatrix block batch from blinded bodies")
 			s.writeErrorResponseToStream(responseCodeServerError, p2ptypes.ErrGeneric.Error(), stream)
 			return err
 		}
-		copy(blks[blindedIndex:], reconstructedBlks)
 	}
 
 	for _, b := range blks {
 		if err := blocks.BeaconBlockIsNil(b); err != nil {
 			continue
 		}
+		if b.IsBlinded() {
+			continue
+		}
+		if chunkErr := s.chunkBlockWriter(stream, b); chunkErr != nil {
+			log.WithError(chunkErr).Debug("Could not send a chunked response")
+			s.writeErrorResponseToStream(responseCodeServerError, p2ptypes.ErrGeneric.Error(), stream)
+			tracing.AnnotateError(span, chunkErr)
+			return chunkErr
+		}
+	}
+
+	for _, b := range reconstructedBlock {
+		if err := blocks.BeaconBlockIsNil(b); err != nil {
+			continue
+		}
+		if b.IsBlinded() {
+			continue
+		}
 		if chunkErr := s.chunkBlockWriter(stream, b); chunkErr != nil {
 			log.WithError(chunkErr).Debug("Could not send a chunked response")
 			s.writeErrorResponseToStream(responseCodeServerError, p2ptypes.ErrGeneric.Error(), stream)
diff --git a/consensus-types/blocks/factory.go b/consensus-types/blocks/factory.go
index 346e5f0c6f..11dd9f3a3a 100644
--- a/consensus-types/blocks/factory.go
+++ b/consensus-types/blocks/factory.go
@@ -28,7 +28,7 @@ var (
 )
 
 // NewSignedBeaconBlock creates a signed beacon block from a protobuf signed beacon block.
-func NewSignedBeaconBlock(i interface{}) (interfaces.SignedBeaconBlock, error) {
+func NewSignedBeaconBlock(i interface{}) (interfaces.SignedBeaconBlockWriteable, error) {
 	switch b := i.(type) {
 	case nil:
 		return nil, ErrNilObject
@@ -120,7 +120,7 @@ func NewBeaconBlockBody(i interface{}) (interfaces.BeaconBlockBody, error) {
 // BuildSignedBeaconBlock assembles a block.SignedBeaconBlock interface compatible struct from a
 // given beacon block and the appropriate signature. This method may be used to easily create a
 // signed beacon block.
-func BuildSignedBeaconBlock(blk interfaces.BeaconBlock, signature []byte) (interfaces.SignedBeaconBlock, error) {
+func BuildSignedBeaconBlock(blk interfaces.BeaconBlock, signature []byte) (interfaces.SignedBeaconBlockWriteable, error) {
 	pb, err := blk.Proto()
 	if err != nil {
 		return nil, err
@@ -174,7 +174,7 @@ func BuildSignedBeaconBlock(blk interfaces.BeaconBlock, signature []byte) (inter
 // a full, signed beacon block by specifying an execution payload.
 func BuildSignedBeaconBlockFromExecutionPayload(
 	blk interfaces.SignedBeaconBlock, payload interface{},
-) (interfaces.SignedBeaconBlock, error) {
+) (interfaces.SignedBeaconBlockWriteable, error) {
 	if err := BeaconBlockIsNil(blk); err != nil {
 		return nil, err
 	}
diff --git a/consensus-types/blocks/getters_test.go b/consensus-types/blocks/getters_test.go
index 07e2592234..17683550d4 100644
--- a/consensus-types/blocks/getters_test.go
+++ b/consensus-types/blocks/getters_test.go
@@ -140,27 +140,27 @@ func Test_SignedBeaconBlock_UnmarshalSSZ(t *testing.T) {
 }
 
 func Test_BeaconBlock_Slot(t *testing.T) {
-	b := &BeaconBlock{}
+	b := &SignedBeaconBlock{block: &BeaconBlock{}}
 	b.SetSlot(128)
-	assert.Equal(t, primitives.Slot(128), b.Slot())
+	assert.Equal(t, primitives.Slot(128), b.Block().Slot())
 }
 
 func Test_BeaconBlock_ProposerIndex(t *testing.T) {
-	b := &BeaconBlock{}
+	b := &SignedBeaconBlock{block: &BeaconBlock{}}
 	b.SetProposerIndex(128)
-	assert.Equal(t, primitives.ValidatorIndex(128), b.ProposerIndex())
+	assert.Equal(t, primitives.ValidatorIndex(128), b.Block().ProposerIndex())
 }
 
 func Test_BeaconBlock_ParentRoot(t *testing.T) {
-	b := &BeaconBlock{}
+	b := &SignedBeaconBlock{block: &BeaconBlock{}}
 	b.SetParentRoot([]byte("parentroot"))
-	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("parentroot")), b.ParentRoot())
+	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("parentroot")), b.Block().ParentRoot())
 }
 
 func Test_BeaconBlock_StateRoot(t *testing.T) {
-	b := &BeaconBlock{}
+	b := &SignedBeaconBlock{block: &BeaconBlock{}}
 	b.SetStateRoot([]byte("stateroot"))
-	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("stateroot")), b.StateRoot())
+	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("stateroot")), b.Block().StateRoot())
 }
 
 func Test_BeaconBlock_Body(t *testing.T) {
@@ -230,7 +230,7 @@ func Test_BeaconBlock_IsNil(t *testing.T) {
 }
 
 func Test_BeaconBlock_IsBlinded(t *testing.T) {
-	b := &BeaconBlock{body: &BeaconBlockBody{}}
+	b := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	assert.Equal(t, false, b.IsBlinded())
 	b.SetBlinded(true)
 	assert.Equal(t, true, b.IsBlinded())
@@ -309,73 +309,73 @@ func Test_BeaconBlockBody_IsNil(t *testing.T) {
 }
 
 func Test_BeaconBlockBody_RandaoReveal(t *testing.T) {
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetRandaoReveal([]byte("randaoreveal"))
-	assert.DeepEqual(t, bytesutil.ToBytes96([]byte("randaoreveal")), bb.RandaoReveal())
+	assert.DeepEqual(t, bytesutil.ToBytes96([]byte("randaoreveal")), bb.Block().Body().RandaoReveal())
 }
 
 func Test_BeaconBlockBody_Eth1Data(t *testing.T) {
 	e := &eth.Eth1Data{DepositRoot: []byte("depositroot")}
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetEth1Data(e)
-	assert.DeepEqual(t, e, bb.Eth1Data())
+	assert.DeepEqual(t, e, bb.Block().Body().Eth1Data())
 }
 
 func Test_BeaconBlockBody_Graffiti(t *testing.T) {
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetGraffiti([]byte("graffiti"))
-	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("graffiti")), bb.Graffiti())
+	assert.DeepEqual(t, bytesutil.ToBytes32([]byte("graffiti")), bb.Block().Body().Graffiti())
 }
 
 func Test_BeaconBlockBody_ProposerSlashings(t *testing.T) {
 	ps := make([]*eth.ProposerSlashing, 0)
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetProposerSlashings(ps)
-	assert.DeepSSZEqual(t, ps, bb.ProposerSlashings())
+	assert.DeepSSZEqual(t, ps, bb.Block().Body().ProposerSlashings())
 }
 
 func Test_BeaconBlockBody_AttesterSlashings(t *testing.T) {
 	as := make([]*eth.AttesterSlashing, 0)
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetAttesterSlashings(as)
-	assert.DeepSSZEqual(t, as, bb.AttesterSlashings())
+	assert.DeepSSZEqual(t, as, bb.Block().Body().AttesterSlashings())
 }
 
 func Test_BeaconBlockBody_Attestations(t *testing.T) {
 	a := make([]*eth.Attestation, 0)
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetAttestations(a)
-	assert.DeepSSZEqual(t, a, bb.Attestations())
+	assert.DeepSSZEqual(t, a, bb.Block().Body().Attestations())
 }
 
 func Test_BeaconBlockBody_Deposits(t *testing.T) {
 	d := make([]*eth.Deposit, 0)
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetDeposits(d)
-	assert.DeepSSZEqual(t, d, bb.Deposits())
+	assert.DeepSSZEqual(t, d, bb.Block().Body().Deposits())
 }
 
 func Test_BeaconBlockBody_VoluntaryExits(t *testing.T) {
 	ve := make([]*eth.SignedVoluntaryExit, 0)
-	bb := &BeaconBlockBody{}
+	bb := &SignedBeaconBlock{block: &BeaconBlock{body: &BeaconBlockBody{}}}
 	bb.SetVoluntaryExits(ve)
-	assert.DeepSSZEqual(t, ve, bb.VoluntaryExits())
+	assert.DeepSSZEqual(t, ve, bb.Block().Body().VoluntaryExits())
 }
 
 func Test_BeaconBlockBody_SyncAggregate(t *testing.T) {
 	sa := &eth.SyncAggregate{}
-	bb := &BeaconBlockBody{version: version.Altair}
+	bb := &SignedBeaconBlock{version: version.Altair, block: &BeaconBlock{version: version.Altair, body: &BeaconBlockBody{version: version.Altair}}}
 	require.NoError(t, bb.SetSyncAggregate(sa))
-	result, err := bb.SyncAggregate()
+	result, err := bb.Block().Body().SyncAggregate()
 	require.NoError(t, err)
 	assert.DeepEqual(t, result, sa)
 }
 
 func Test_BeaconBlockBody_BLSToExecutionChanges(t *testing.T) {
 	changes := []*eth.SignedBLSToExecutionChange{{Message: &eth.BLSToExecutionChange{ToExecutionAddress: []byte("address")}}}
-	bb := &BeaconBlockBody{version: version.Capella}
+	bb := &SignedBeaconBlock{version: version.Capella, block: &BeaconBlock{body: &BeaconBlockBody{version: version.Capella}}}
 	require.NoError(t, bb.SetBLSToExecutionChanges(changes))
-	result, err := bb.BLSToExecutionChanges()
+	result, err := bb.Block().Body().BLSToExecutionChanges()
 	require.NoError(t, err)
 	assert.DeepSSZEqual(t, result, changes)
 }
@@ -384,27 +384,27 @@ func Test_BeaconBlockBody_Execution(t *testing.T) {
 	execution := &pb.ExecutionPayload{BlockNumber: 1}
 	e, err := WrappedExecutionPayload(execution)
 	require.NoError(t, err)
-	bb := &BeaconBlockBody{version: version.Bellatrix}
+	bb := &SignedBeaconBlock{version: version.Bellatrix, block: &BeaconBlock{body: &BeaconBlockBody{version: version.Bellatrix}}}
 	require.NoError(t, bb.SetExecution(e))
-	result, err := bb.Execution()
+	result, err := bb.Block().Body().Execution()
 	require.NoError(t, err)
 	assert.DeepEqual(t, result, e)
 
 	executionCapella := &pb.ExecutionPayloadCapella{BlockNumber: 1}
 	eCapella, err := WrappedExecutionPayloadCapella(executionCapella)
 	require.NoError(t, err)
-	bb = &BeaconBlockBody{version: version.Capella}
+	bb = &SignedBeaconBlock{version: version.Capella, block: &BeaconBlock{body: &BeaconBlockBody{version: version.Capella}}}
 	require.NoError(t, bb.SetExecution(eCapella))
-	result, err = bb.Execution()
+	result, err = bb.Block().Body().Execution()
 	require.NoError(t, err)
 	assert.DeepEqual(t, result, eCapella)
 
 	executionCapellaHeader := &pb.ExecutionPayloadHeaderCapella{BlockNumber: 1}
 	eCapellaHeader, err := WrappedExecutionPayloadHeaderCapella(executionCapellaHeader)
 	require.NoError(t, err)
-	bb = &BeaconBlockBody{version: version.Capella, isBlinded: true}
+	bb = &SignedBeaconBlock{version: version.Capella, block: &BeaconBlock{version: version.Capella, body: &BeaconBlockBody{version: version.Capella, isBlinded: true}}}
 	require.NoError(t, bb.SetExecution(eCapellaHeader))
-	result, err = bb.Execution()
+	result, err = bb.Block().Body().Execution()
 	require.NoError(t, err)
 	assert.DeepEqual(t, result, eCapellaHeader)
 }
diff --git a/consensus-types/blocks/setters.go b/consensus-types/blocks/setters.go
index 656a0ab7ea..ed8ca4f0f6 100644
--- a/consensus-types/blocks/setters.go
+++ b/consensus-types/blocks/setters.go
@@ -15,112 +15,112 @@ func (b *SignedBeaconBlock) SetSignature(sig []byte) {
 
 // SetSlot sets the respective slot of the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlock) SetSlot(slot primitives.Slot) {
-	b.slot = slot
+func (b *SignedBeaconBlock) SetSlot(slot primitives.Slot) {
+	b.block.slot = slot
 }
 
 // SetProposerIndex sets the proposer index of the beacon block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlock) SetProposerIndex(proposerIndex primitives.ValidatorIndex) {
-	b.proposerIndex = proposerIndex
+func (b *SignedBeaconBlock) SetProposerIndex(proposerIndex primitives.ValidatorIndex) {
+	b.block.proposerIndex = proposerIndex
 }
 
 // SetParentRoot sets the parent root of beacon block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlock) SetParentRoot(parentRoot []byte) {
-	copy(b.parentRoot[:], parentRoot)
+func (b *SignedBeaconBlock) SetParentRoot(parentRoot []byte) {
+	copy(b.block.parentRoot[:], parentRoot)
 }
 
 // SetStateRoot sets the state root of the underlying beacon block
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlock) SetStateRoot(root []byte) {
-	copy(b.stateRoot[:], root)
+func (b *SignedBeaconBlock) SetStateRoot(root []byte) {
+	copy(b.block.stateRoot[:], root)
 }
 
 // SetBlinded sets the blinded flag of the beacon block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlock) SetBlinded(blinded bool) {
-	b.body.isBlinded = blinded
+func (b *SignedBeaconBlock) SetBlinded(blinded bool) {
+	b.block.body.isBlinded = blinded
 }
 
 // SetRandaoReveal sets the randao reveal in the block body.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetRandaoReveal(r []byte) {
-	copy(b.randaoReveal[:], r)
+func (b *SignedBeaconBlock) SetRandaoReveal(r []byte) {
+	copy(b.block.body.randaoReveal[:], r)
 }
 
 // SetGraffiti sets the graffiti in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetGraffiti(g []byte) {
-	copy(b.graffiti[:], g)
+func (b *SignedBeaconBlock) SetGraffiti(g []byte) {
+	copy(b.block.body.graffiti[:], g)
 }
 
 // SetEth1Data sets the eth1 data in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetEth1Data(e *eth.Eth1Data) {
-	b.eth1Data = e
+func (b *SignedBeaconBlock) SetEth1Data(e *eth.Eth1Data) {
+	b.block.body.eth1Data = e
 }
 
 // SetProposerSlashings sets the proposer slashings in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetProposerSlashings(p []*eth.ProposerSlashing) {
-	b.proposerSlashings = p
+func (b *SignedBeaconBlock) SetProposerSlashings(p []*eth.ProposerSlashing) {
+	b.block.body.proposerSlashings = p
 }
 
 // SetAttesterSlashings sets the attester slashings in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetAttesterSlashings(a []*eth.AttesterSlashing) {
-	b.attesterSlashings = a
+func (b *SignedBeaconBlock) SetAttesterSlashings(a []*eth.AttesterSlashing) {
+	b.block.body.attesterSlashings = a
 }
 
 // SetAttestations sets the attestations in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetAttestations(a []*eth.Attestation) {
-	b.attestations = a
+func (b *SignedBeaconBlock) SetAttestations(a []*eth.Attestation) {
+	b.block.body.attestations = a
 }
 
 // SetDeposits sets the deposits in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetDeposits(d []*eth.Deposit) {
-	b.deposits = d
+func (b *SignedBeaconBlock) SetDeposits(d []*eth.Deposit) {
+	b.block.body.deposits = d
 }
 
 // SetVoluntaryExits sets the voluntary exits in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetVoluntaryExits(v []*eth.SignedVoluntaryExit) {
-	b.voluntaryExits = v
+func (b *SignedBeaconBlock) SetVoluntaryExits(v []*eth.SignedVoluntaryExit) {
+	b.block.body.voluntaryExits = v
 }
 
 // SetSyncAggregate sets the sync aggregate in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetSyncAggregate(s *eth.SyncAggregate) error {
+func (b *SignedBeaconBlock) SetSyncAggregate(s *eth.SyncAggregate) error {
 	if b.version == version.Phase0 {
 		return ErrNotSupported("SyncAggregate", b.version)
 	}
-	b.syncAggregate = s
+	b.block.body.syncAggregate = s
 	return nil
 }
 
 // SetExecution sets the execution payload of the block body.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetExecution(e interfaces.ExecutionData) error {
+func (b *SignedBeaconBlock) SetExecution(e interfaces.ExecutionData) error {
 	if b.version == version.Phase0 || b.version == version.Altair {
 		return ErrNotSupported("Execution", b.version)
 	}
-	if b.isBlinded {
-		b.executionPayloadHeader = e
+	if b.block.body.isBlinded {
+		b.block.body.executionPayloadHeader = e
 		return nil
 	}
-	b.executionPayload = e
+	b.block.body.executionPayload = e
 	return nil
 }
 
 // SetBLSToExecutionChanges sets the BLS to execution changes in the block.
 // This function is not thread safe, it is only used during block creation.
-func (b *BeaconBlockBody) SetBLSToExecutionChanges(blsToExecutionChanges []*eth.SignedBLSToExecutionChange) error {
+func (b *SignedBeaconBlock) SetBLSToExecutionChanges(blsToExecutionChanges []*eth.SignedBLSToExecutionChange) error {
 	if b.version < version.Capella {
 		return ErrNotSupported("BLSToExecutionChanges", b.version)
 	}
-	b.blsToExecutionChanges = blsToExecutionChanges
+	b.block.body.blsToExecutionChanges = blsToExecutionChanges
 	return nil
 }
diff --git a/consensus-types/blocks/testing/mutator.go b/consensus-types/blocks/testing/mutator.go
index 23da634a07..c7e2a2ddfd 100644
--- a/consensus-types/blocks/testing/mutator.go
+++ b/consensus-types/blocks/testing/mutator.go
@@ -15,7 +15,7 @@ type blockMutator struct {
 	Capella   func(beaconBlock *eth.SignedBeaconBlockCapella)
 }
 
-func (m blockMutator) apply(b interfaces.SignedBeaconBlock) (interfaces.SignedBeaconBlock, error) {
+func (m blockMutator) apply(b interfaces.SignedBeaconBlockWriteable) (interfaces.SignedBeaconBlockWriteable, error) {
 	switch b.Version() {
 	case version.Phase0:
 		bb, err := b.PbPhase0Block()
@@ -51,7 +51,7 @@ func (m blockMutator) apply(b interfaces.SignedBeaconBlock) (interfaces.SignedBe
 }
 
 // SetBlockStateRoot modifies the block's state root.
-func SetBlockStateRoot(b interfaces.SignedBeaconBlock, sr [32]byte) (interfaces.SignedBeaconBlock, error) {
+func SetBlockStateRoot(b interfaces.SignedBeaconBlockWriteable, sr [32]byte) (interfaces.SignedBeaconBlockWriteable, error) {
 	return blockMutator{
 		Phase0:    func(bb *eth.SignedBeaconBlock) { bb.Block.StateRoot = sr[:] },
 		Altair:    func(bb *eth.SignedBeaconBlockAltair) { bb.Block.StateRoot = sr[:] },
@@ -61,7 +61,7 @@ func SetBlockStateRoot(b interfaces.SignedBeaconBlock, sr [32]byte) (interfaces.
 }
 
 // SetBlockParentRoot modifies the block's parent root.
-func SetBlockParentRoot(b interfaces.SignedBeaconBlock, pr [32]byte) (interfaces.SignedBeaconBlock, error) {
+func SetBlockParentRoot(b interfaces.SignedBeaconBlockWriteable, pr [32]byte) (interfaces.SignedBeaconBlockWriteable, error) {
 	return blockMutator{
 		Phase0:    func(bb *eth.SignedBeaconBlock) { bb.Block.ParentRoot = pr[:] },
 		Altair:    func(bb *eth.SignedBeaconBlockAltair) { bb.Block.ParentRoot = pr[:] },
@@ -71,7 +71,7 @@ func SetBlockParentRoot(b interfaces.SignedBeaconBlock, pr [32]byte) (interfaces
 }
 
 // SetBlockSlot modifies the block's slot.
-func SetBlockSlot(b interfaces.SignedBeaconBlock, s primitives.Slot) (interfaces.SignedBeaconBlock, error) {
+func SetBlockSlot(b interfaces.SignedBeaconBlockWriteable, s primitives.Slot) (interfaces.SignedBeaconBlockWriteable, error) {
 	return blockMutator{
 		Phase0:    func(bb *eth.SignedBeaconBlock) { bb.Block.Slot = s },
 		Altair:    func(bb *eth.SignedBeaconBlockAltair) { bb.Block.Slot = s },
@@ -81,7 +81,7 @@ func SetBlockSlot(b interfaces.SignedBeaconBlock, s primitives.Slot) (interfaces
 }
 
 // SetProposerIndex modifies the block's proposer index.
-func SetProposerIndex(b interfaces.SignedBeaconBlock, idx primitives.ValidatorIndex) (interfaces.SignedBeaconBlock, error) {
+func SetProposerIndex(b interfaces.SignedBeaconBlockWriteable, idx primitives.ValidatorIndex) (interfaces.SignedBeaconBlockWriteable, error) {
 	return blockMutator{
 		Phase0:    func(bb *eth.SignedBeaconBlock) { bb.Block.ProposerIndex = idx },
 		Altair:    func(bb *eth.SignedBeaconBlockAltair) { bb.Block.ProposerIndex = idx },
diff --git a/consensus-types/interfaces/beacon_block.go b/consensus-types/interfaces/beacon_block.go
index fbf860ec8b..45636c3e33 100644
--- a/consensus-types/interfaces/beacon_block.go
+++ b/consensus-types/interfaces/beacon_block.go
@@ -15,7 +15,6 @@ import (
 type SignedBeaconBlock interface {
 	Block() BeaconBlock
 	Signature() [field_params.BLSSignatureLength]byte
-	SetSignature(sig []byte)
 	IsNil() bool
 	Copy() (SignedBeaconBlock, error)
 	Proto() (proto.Message, error)
@@ -38,17 +37,12 @@ type SignedBeaconBlock interface {
 // employed by an object that is a beacon block.
 type BeaconBlock interface {
 	Slot() primitives.Slot
-	SetSlot(slot primitives.Slot)
 	ProposerIndex() primitives.ValidatorIndex
-	SetProposerIndex(idx primitives.ValidatorIndex)
 	ParentRoot() [field_params.RootLength]byte
-	SetParentRoot([]byte)
 	StateRoot() [field_params.RootLength]byte
-	SetStateRoot([]byte)
 	Body() BeaconBlockBody
 	IsNil() bool
 	IsBlinded() bool
-	SetBlinded(bool)
 	HashTreeRoot() ([field_params.RootLength]byte, error)
 	Proto() (proto.Message, error)
 	ssz.Marshaler
@@ -63,30 +57,40 @@ type BeaconBlock interface {
 // that is a beacon block body.
 type BeaconBlockBody interface {
 	RandaoReveal() [field_params.BLSSignatureLength]byte
-	SetRandaoReveal([]byte)
 	Eth1Data() *ethpb.Eth1Data
-	SetEth1Data(*ethpb.Eth1Data)
 	Graffiti() [field_params.RootLength]byte
-	SetGraffiti([]byte)
 	ProposerSlashings() []*ethpb.ProposerSlashing
-	SetProposerSlashings([]*ethpb.ProposerSlashing)
 	AttesterSlashings() []*ethpb.AttesterSlashing
-	SetAttesterSlashings([]*ethpb.AttesterSlashing)
 	Attestations() []*ethpb.Attestation
-	SetAttestations([]*ethpb.Attestation)
 	Deposits() []*ethpb.Deposit
-	SetDeposits([]*ethpb.Deposit)
 	VoluntaryExits() []*ethpb.SignedVoluntaryExit
-	SetVoluntaryExits([]*ethpb.SignedVoluntaryExit)
 	SyncAggregate() (*ethpb.SyncAggregate, error)
-	SetSyncAggregate(*ethpb.SyncAggregate) error
 	IsNil() bool
 	HashTreeRoot() ([field_params.RootLength]byte, error)
 	Proto() (proto.Message, error)
 	Execution() (ExecutionData, error)
-	SetExecution(ExecutionData) error
 	BLSToExecutionChanges() ([]*ethpb.SignedBLSToExecutionChange, error)
+}
+
+type SignedBeaconBlockWriteable interface {
+	SignedBeaconBlock
+	SetExecution(ExecutionData) error
 	SetBLSToExecutionChanges([]*ethpb.SignedBLSToExecutionChange) error
+	SetSyncAggregate(*ethpb.SyncAggregate) error
+	SetVoluntaryExits([]*ethpb.SignedVoluntaryExit)
+	SetDeposits([]*ethpb.Deposit)
+	SetAttestations([]*ethpb.Attestation)
+	SetAttesterSlashings([]*ethpb.AttesterSlashing)
+	SetProposerSlashings([]*ethpb.ProposerSlashing)
+	SetGraffiti([]byte)
+	SetEth1Data(*ethpb.Eth1Data)
+	SetRandaoReveal([]byte)
+	SetBlinded(bool)
+	SetStateRoot([]byte)
+	SetParentRoot([]byte)
+	SetProposerIndex(idx primitives.ValidatorIndex)
+	SetSlot(slot primitives.Slot)
+	SetSignature(sig []byte)
 }
 
 // ExecutionData represents execution layer information that is contained
diff --git a/testing/util/block.go b/testing/util/block.go
index 759aba9942..039bdab836 100644
--- a/testing/util/block.go
+++ b/testing/util/block.go
@@ -1109,7 +1109,7 @@ func HydrateV2BlindedBeaconBlockBodyCapella(b *v2.BlindedBeaconBlockBodyCapella)
 	return b
 }
 
-func SaveBlock(tb assertions.AssertionTestingTB, ctx context.Context, db iface.NoHeadAccessDatabase, b interface{}) interfaces.SignedBeaconBlock {
+func SaveBlock(tb assertions.AssertionTestingTB, ctx context.Context, db iface.NoHeadAccessDatabase, b interface{}) interfaces.SignedBeaconBlockWriteable {
 	wsb, err := blocks.NewSignedBeaconBlock(b)
 	require.NoError(tb, err)
 	require.NoError(tb, db.SaveBlock(ctx, wsb))