diff --git a/beacon/blsync/block_sync.go b/beacon/blsync/block_sync.go
index b2fa42f696..91b21163e6 100755
--- a/beacon/blsync/block_sync.go
+++ b/beacon/blsync/block_sync.go
@@ -166,7 +166,7 @@ func getExecBlock(beaconBlock *capella.BeaconBlock) (*ctypes.Block, error) {
 	}
 	execBlock := ctypes.NewBlockWithHeader(execHeader).WithBody(txs, nil).WithWithdrawals(withdrawals)
 	if execBlockHash := execBlock.Hash(); execBlockHash != common.Hash(payload.BlockHash) {
-		return nil, fmt.Errorf("Sanity check failed, payload hash does not match (expected %x, got %x)", common.Hash(payload.BlockHash), execBlockHash)
+		return execBlock, fmt.Errorf("Sanity check failed, payload hash does not match (expected %x, got %x)", common.Hash(payload.BlockHash), execBlockHash)
 	}
 	return execBlock, nil
 }
diff --git a/beacon/blsync/block_sync_test.go b/beacon/blsync/block_sync_test.go
index 4227be48af..a2546279ed 100644
--- a/beacon/blsync/block_sync_test.go
+++ b/beacon/blsync/block_sync_test.go
@@ -23,6 +23,7 @@ import (
 	"github.com/ethereum/go-ethereum/beacon/light/sync"
 	"github.com/ethereum/go-ethereum/beacon/types"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/event"
 	"github.com/protolambda/zrnt/eth2/beacon/capella"
 	"github.com/protolambda/zrnt/eth2/configs"
 	"github.com/protolambda/ztyp/tree"
@@ -32,27 +33,49 @@ var (
 	testServer1 = "testServer1"
 	testServer2 = "testServer2"
 
-	testBlock1 = &capella.BeaconBlock{Slot: 123}
-	testBlock2 = &capella.BeaconBlock{Slot: 124}
+	testBlock1 = &capella.BeaconBlock{
+		Slot: 123,
+		Body: capella.BeaconBlockBody{
+			ExecutionPayload: capella.ExecutionPayload{BlockNumber: 456},
+		},
+	}
+	testBlock2 = &capella.BeaconBlock{
+		Slot: 124,
+		Body: capella.BeaconBlockBody{
+			ExecutionPayload: capella.ExecutionPayload{BlockNumber: 457},
+		},
+	}
 )
 
+func init() {
+	eb1, _ := getExecBlock(testBlock1)
+	testBlock1.Body.ExecutionPayload.BlockHash = tree.Root(eb1.Hash())
+	eb2, _ := getExecBlock(testBlock2)
+	testBlock2.Body.ExecutionPayload.BlockHash = tree.Root(eb2.Hash())
+}
+
 func TestBlockSync(t *testing.T) {
 	ht := &testHeadTracker{}
-	blockSync := newBeaconBlockSync(ht)
+	eventFeed := new(event.Feed)
+	blockSync := newBeaconBlockSync(ht, eventFeed)
+	headCh := make(chan types.ChainHeadEvent, 16)
+	eventFeed.Subscribe(headCh)
 	ts := sync.NewTestScheduler(t, blockSync)
 	ts.AddServer(testServer1, 1)
 	ts.AddServer(testServer2, 1)
 
 	expHeadBlock := func(tci int, expHead *capella.BeaconBlock) {
-		expInfo := blockHeadInfo(expHead)
-		var head headData
+		var expNumber, headNumber uint64
+		if expHead != nil {
+			expNumber = uint64(expHead.Body.ExecutionPayload.BlockNumber)
+		}
 		select {
-		case head = <-blockSync.headCh:
+		case event := <-headCh:
+			headNumber = event.HeadBlock.Number
 		default:
 		}
-		headInfo := blockHeadInfo(head.block)
-		if headInfo != expInfo {
-			t.Errorf("Wrong head block in test case #%d (expected {slot %d blockRoot %x}, got {slot %d blockRoot %x})", tci, expInfo.Slot, expInfo.BlockRoot, headInfo.Slot, headInfo.BlockRoot)
+		if headNumber != expNumber {
+			t.Errorf("Wrong head block in test case #%d (expected block number %d, got %d)", tci, expNumber, headNumber)
 		}
 	}
 
@@ -130,6 +153,7 @@ func (h *testHeadTracker) ValidatedHead() (types.SignedHeader, bool) {
 func (h *testHeadTracker) ValidatedFinality() (types.FinalityUpdate, bool) {
 	return types.FinalityUpdate{
 		Attested:      types.HeaderWithExecProof{Header: h.validated.Header},
+		Finalized:     types.HeaderWithExecProof{PayloadHeader: &capella.ExecutionPayloadHeader{}},
 		Signature:     h.validated.Signature,
 		SignatureSlot: h.validated.SignatureSlot,
 	}, h.validated.Header != (types.Header{})
diff --git a/cmd/blsync/main.go b/cmd/blsync/main.go
index 422a4943eb..fd22761d3c 100644
--- a/cmd/blsync/main.go
+++ b/cmd/blsync/main.go
@@ -87,7 +87,7 @@ func sync(ctx *cli.Context) error {
 	verbosity := log.FromLegacyLevel(ctx.Int(verbosityFlag.Name))
 	log.SetDefault(log.NewLogger(log.NewTerminalHandlerWithLevel(output, verbosity, usecolor)))
 
-	headCh := make(chan types.ChainHeadEvent, 1)
+	headCh := make(chan types.ChainHeadEvent, 16)
 	client := blsync.NewClient(ctx)
 	sub := client.SubscribeChainHeadEvent(headCh)
 	go updateEngineApi(makeRPCClient(ctx), headCh)
diff --git a/eth/catalyst/blsync.go b/eth/catalyst/blsync.go
index 8f86afa95a..4877cf4c63 100644
--- a/eth/catalyst/blsync.go
+++ b/eth/catalyst/blsync.go
@@ -46,7 +46,7 @@ func NewBlsync(client Client, eth *eth.Ethereum) *Blsync {
 	return &Blsync{
 		engine: newConsensusAPIWithoutHeartbeat(eth),
 		client: client,
-		headCh: make(chan types.ChainHeadEvent, 1),
+		headCh: make(chan types.ChainHeadEvent, 16),
 		quitCh: make(chan struct{}),
 	}
 }