diff --git a/fluffy/rpc/rpc_eth_api.nim b/fluffy/rpc/rpc_eth_api.nim
index b50bca74f..4eac3bfc4 100644
--- a/fluffy/rpc/rpc_eth_api.nim
+++ b/fluffy/rpc/rpc_eth_api.nim
@@ -46,7 +46,7 @@ func init*(
 ): T {.raises: [ValidationError].} =
   TransactionObject(
     blockHash: some(w3Hash header.blockHash),
-    blockNumber: some(Quantity(header.blockNumber.truncate(uint64))),
+    blockNumber: some(rpc_types.BlockNumber(header.blockNumber.truncate(uint64))),
     `from`: w3Addr tx.getSender(),
     gas: Quantity(tx.gasLimit),
     gasPrice: Quantity(tx.gasPrice),
@@ -76,7 +76,7 @@ func init*(
   let blockHash = header.blockHash
 
   var blockObject = BlockObject(
-    number: Quantity(header.blockNumber.truncate(uint64)),
+    number: rpc_types.BlockNumber(header.blockNumber.truncate(uint64)),
     hash: w3Hash blockHash,
     parentHash: w3Hash header.parentHash,
     nonce: some(FixedBytes[8](header.nonce)),
@@ -272,7 +272,7 @@ proc installEthApiHandlers*(
         raise newException(ValueError, "Unsupported block tag " & tag)
     else:
       let
-        blockNumber = quantityTag.number.toBlockNumber
+        blockNumber = quantityTag.number.uint64.toBlockNumber
         maybeBlock = (await historyNetwork.getBlock(blockNumber)).valueOr:
           raise newException(ValueError, error)
 
diff --git a/fluffy/tools/blockwalk.nim b/fluffy/tools/blockwalk.nim
index ac0d549fc..0a3d515b9 100644
--- a/fluffy/tools/blockwalk.nim
+++ b/fluffy/tools/blockwalk.nim
@@ -56,10 +56,10 @@ proc completeCmdArg*(T: type BlockHash, val: string): seq[string] =
 
 proc walkBlocks(client: RpcClient, startHash: BlockHash) {.async: (raises: []).} =
   var parentHash = startHash
-  var blockNumber: Quantity
+  var blockNumber: BlockNumber
 
   # Should be 0x0, but block 0 does not exist in the json data file
-  while blockNumber != Quantity(0x1):
+  while blockNumber != BlockNumber(0x1):
     let parentBlockOpt =
       try:
         await client.eth_getBlockByHash(parentHash, false)
diff --git a/hive_integration/nodocker/engine/engine_client.nim b/hive_integration/nodocker/engine/engine_client.nim
index 03e8d0abb..45df5d185 100644
--- a/hive_integration/nodocker/engine/engine_client.nim
+++ b/hive_integration/nodocker/engine/engine_client.nim
@@ -221,6 +221,11 @@ proc maybeU64(n: Option[Quantity]): Option[uint64] =
     return none(uint64)
   some(n.get.uint64)
 
+proc maybeU64(n: Option[Web3BlockNumber]): Option[uint64] =
+  if n.isNone:
+    return none(uint64)
+  some(n.get.uint64)
+
 proc maybeBool(n: Option[Quantity]): Option[bool] =
   if n.isNone:
     return none(bool)
@@ -238,7 +243,7 @@ proc maybeInt(n: Option[Quantity]): Option[int] =
 
 proc toBlockHeader*(bc: BlockObject): common.BlockHeader =
   common.BlockHeader(
-    blockNumber    : toBlockNumber(bc.number),
+    blockNumber    : bc.number.u256,
     parentHash     : ethHash bc.parentHash,
     nonce          : toBlockNonce(bc.nonce),
     ommersHash     : ethHash bc.sha3Uncles,
@@ -538,7 +543,7 @@ proc verifyPoWProgress*(client: RpcClient, lastBlockHash: Hash256): Future[Resul
     return err("cannot get block by hash " & lastBlockHash.data.toHex)
 
   let header = res
-  let number = toBlockNumber(header.number)
+  let number = header.number.u256
 
   let period = chronos.seconds(3)
   var loop = 0
@@ -554,7 +559,7 @@ proc verifyPoWProgress*(client: RpcClient, lastBlockHash: Hash256): Future[Resul
     if diff.isZero:
       return err("Expected PoW chain to progress in PoW mode, but following block difficulty: " & $diff)
 
-    if toBlockNumber(bc.number) > number:
+    if bc.number.u256 > number:
       return ok()
 
     await sleepAsync(period)
diff --git a/nimbus/beacon/web3_eth_conv.nim b/nimbus/beacon/web3_eth_conv.nim
index 1f7af8ad2..0c2df2cd0 100644
--- a/nimbus/beacon/web3_eth_conv.nim
+++ b/nimbus/beacon/web3_eth_conv.nim
@@ -22,16 +22,17 @@ export
   primitives
 
 type
-  Web3Hash*       = web3types.Hash256
-  Web3Address*    = web3types.Address
-  Web3Bloom*      = web3types.FixedBytes[256]
-  Web3Quantity*   = web3types.Quantity
-  Web3PrevRandao* = web3types.FixedBytes[32]
-  Web3ExtraData*  = web3types.DynamicBytes[0, 32]
-  Web3Topic*      = eth_api_types.Topic
-  Web3Tx*         = engine_api_types.TypedTransaction
-  Web3Blob*       = engine_api_types.Blob
-  Web3KZGProof*   = engine_api_types.KZGProof
+  Web3Hash*          = web3types.Hash256
+  Web3Address*       = web3types.Address
+  Web3Bloom*         = web3types.FixedBytes[256]
+  Web3Quantity*      = web3types.Quantity
+  Web3PrevRandao*    = web3types.FixedBytes[32]
+  Web3ExtraData*     = web3types.DynamicBytes[0, 32]
+  Web3BlockNumber*   = web3types.BlockNumber
+  Web3Topic*         = eth_api_types.Topic
+  Web3Tx*            = engine_api_types.TypedTransaction
+  Web3Blob*          = engine_api_types.Blob
+  Web3KZGProof*      = engine_api_types.KZGProof
   Web3KZGCommitment* = engine_api_types.KZGCommitment
 
 {.push gcsafe, raises:[].}
@@ -86,6 +87,9 @@ func u64*(x: Option[Web3Quantity]): Option[uint64] =
 func u256*(x: Web3Quantity): UInt256 =
   u256(x.uint64)
 
+func u256*(x: Web3BlockNumber): UInt256 =
+  u256(x.uint64)
+
 func u256*(x: FixedBytes[32]): UInt256 =
   UInt256.fromBytesBE(x.bytes)
 
@@ -221,6 +225,16 @@ func w3Qty*(x: Option[uint64]): Option[Web3Quantity] =
 func w3Qty*(x: uint64): Web3Quantity =
   Web3Quantity(x)
 
+func w3BlockNumber*(x: Option[uint64]): Option[Web3BlockNumber] =
+  if x.isNone: none(Web3BlockNumber)
+  else: some(Web3BlockNumber x.get)
+
+func w3BlockNumber*(x: uint64): Web3BlockNumber =
+  Web3BlockNumber(x)
+
+func w3BlockNumber*(x: UInt256): Web3BlockNumber =
+  Web3BlockNumber x.truncate(uint64)
+
 func w3FixedBytes*(x: UInt256): FixedBytes[32] =
   FixedBytes[32](x.toBytesBE)
 
diff --git a/nimbus/evm/async/data_sources/json_rpc_data_source.nim b/nimbus/evm/async/data_sources/json_rpc_data_source.nim
index 836298b09..dc1e81992 100644
--- a/nimbus/evm/async/data_sources/json_rpc_data_source.nim
+++ b/nimbus/evm/async/data_sources/json_rpc_data_source.nim
@@ -79,7 +79,7 @@ proc fetchBlockHeaderWithHash*(rpcClient: RpcClient, h: common.Hash256): Future[
 
 proc fetchBlockHeaderWithNumber*(rpcClient: RpcClient, n: common.BlockNumber): Future[common.BlockHeader] {.async.} =
   let t0 = now()
-  let bid = blockId(n.truncate(uint64))
+  let bid = blockId(w3BlockNumber n)
   let blockObject: BlockObject = await rpcClient.eth_getBlockByNumber(bid, false)
   durationSpentDoingFetches += now() - t0
   fetchCounter += 1
@@ -141,7 +141,7 @@ proc fetchAccountAndSlots*(rpcClient: RpcClient, address: EthAddress, slots: seq
   debug "Got to fetchAccountAndSlots", address=address, slots=slots, blockNumber=blockNumber
   #let blockNumberUint64 = blockNumber.truncate(uint64)
   let a = web3.Address(address)
-  let bid = blockId(blockNumber.truncate(uint64))
+  let bid = blockId(w3BlockNumber blockNumber)
   debug "About to call eth_getProof", address=address, slots=slots, blockNumber=blockNumber
   let proofResponse: ProofResponse = await rpcClient.eth_getProof(a, slots, bid)
   debug "Received response to eth_getProof", proofResponse=proofResponse
@@ -161,7 +161,7 @@ proc fetchAccountAndSlots*(rpcClient: RpcClient, address: EthAddress, slots: seq
 proc fetchCode*(client: RpcClient, blockNumber: common.BlockNumber, address: EthAddress): Future[seq[byte]] {.async.} =
   let t0 = now()
   let a = web3.Address(address)
-  let bid = blockId(blockNumber.truncate(uint64))
+  let bid = blockId(w3BlockNumber blockNumber)
   let fetchedCode: seq[byte] = await client.eth_getCode(a, bid)
   durationSpentDoingFetches += now() - t0
   fetchCounter += 1
diff --git a/nimbus/rpc/filters.nim b/nimbus/rpc/filters.nim
index 3630cf174..9c42b968f 100644
--- a/nimbus/rpc/filters.nim
+++ b/nimbus/rpc/filters.nim
@@ -47,7 +47,7 @@ proc deriveLogs*(header: BlockHeader, transactions: seq[Transaction], receipts:
         transactionIndex: some(w3Qty(i)),
         transactionHash: some(w3Hash transactions[i].rlpHash),
         blockHash: some(w3Hash header.blockHash),
-        blockNumber: some(w3Qty(header.blockNumber.truncate(uint64))),
+        blockNumber: some(w3BlockNumber(header.blockNumber)),
         address: w3Addr log.address,
         data: log.data,
         #  TODO topics should probably be kept as Hash256 in receipts
diff --git a/nimbus/rpc/p2p.nim b/nimbus/rpc/p2p.nim
index c2fdbaf68..872bb328e 100644
--- a/nimbus/rpc/p2p.nim
+++ b/nimbus/rpc/p2p.nim
@@ -246,11 +246,11 @@ proc setupEthRpc*(
       raise newException(ValueError, "Account locked, please unlock it first")
     result = sign(acc.privateKey, cast[string](message))
 
-  server.rpc("eth_signTransaction") do(data: EthSend) -> seq[byte]:
+  server.rpc("eth_signTransaction") do(data: TransactionArgs) -> seq[byte]:
     ## Signs a transaction that can be submitted to the network at a later time using with
     ## eth_sendRawTransaction
     let
-      address = data.`from`.ethAddr
+      address = data.`from`.get(w3Address()).ethAddr
       acc     = ctx.am.getAccount(address).tryGet()
 
     if not acc.unlocked:
@@ -263,14 +263,14 @@ proc setupEthRpc*(
       signedTx = signTransaction(tx, acc.privateKey, com.chainId, eip155)
     result    = rlp.encode(signedTx)
 
-  server.rpc("eth_sendTransaction") do(data: EthSend) -> Web3Hash:
+  server.rpc("eth_sendTransaction") do(data: TransactionArgs) -> Web3Hash:
     ## Creates new message call transaction or a contract creation, if the data field contains code.
     ##
     ## obj: the transaction object.
     ## Returns the transaction hash, or the zero hash if the transaction is not yet available.
     ## Note: Use eth_getTransactionReceipt to get the contract address, after the transaction was mined, when you created a contract.
     let
-      address = data.`from`.ethAddr
+      address = data.`from`.get(w3Address()).ethAddr
       acc     = ctx.am.getAccount(address).tryGet()
 
     if not acc.unlocked:
@@ -301,7 +301,7 @@ proc setupEthRpc*(
       raise newException(ValueError, res.error)
     result = txHash.w3Hash
 
-  server.rpc("eth_call") do(call: EthCall, quantityTag: BlockTag) -> seq[byte]:
+  server.rpc("eth_call") do(call: TransactionArgs, quantityTag: BlockTag) -> seq[byte]:
     ## Executes a new message call immediately without creating a transaction on the block chain.
     ##
     ## call: the transaction call object.
@@ -313,7 +313,7 @@ proc setupEthRpc*(
       res      = rpcCallEvm(callData, header, com)
     result = res.output
 
-  server.rpc("eth_estimateGas") do(call: EthCall) -> Web3Quantity:
+  server.rpc("eth_estimateGas") do(call: TransactionArgs) -> Web3Quantity:
     ## Generates and returns an estimate of how much gas is necessary to allow the transaction to complete.
     ## The transaction will not be added to the blockchain. Note that the estimate may be significantly more than
     ## the amount of gas actually used by the transaction, for a variety of reasons including EVM mechanics and node performance.
@@ -322,7 +322,6 @@ proc setupEthRpc*(
     ## quantityTag:  integer block number, or the string "latest", "earliest" or "pending", see the default block parameter.
     ## Returns the amount of gas used.
     let
-      # TODO: use latest spec EthCall
       header   = chainDB.headerFromTag(blockId("latest"))
       callData = callData(call)
       # TODO: DEFAULT_RPC_GAS_CAP should configurable
diff --git a/nimbus/rpc/rpc_utils.nim b/nimbus/rpc/rpc_utils.nim
index 6cc70e1c0..9cc9be01b 100644
--- a/nimbus/rpc/rpc_utils.nim
+++ b/nimbus/rpc/rpc_utils.nim
@@ -43,7 +43,7 @@ proc headerFromTag*(chain: CoreDbRef, blockId: BlockTag): BlockHeader
     else:
       raise newException(ValueError, "Unsupported block tag " & tag)
   else:
-    let blockNum = blockId.number.toBlockNumber
+    let blockNum = blockId.number.uint64.toBlockNumber
     result = chain.getBlockHeader(blockNum)
 
 proc headerFromTag*(chain: CoreDbRef, blockTag: Option[BlockTag]): BlockHeader
@@ -69,7 +69,7 @@ proc calculateMedianGasPrice*(chain: CoreDbRef): GasInt
     else:
       result = prices[middle]
 
-proc unsignedTx*(tx: EthSend, chain: CoreDbRef, defaultNonce: AccountNonce): Transaction
+proc unsignedTx*(tx: TransactionArgs, chain: CoreDbRef, defaultNonce: AccountNonce): Transaction
     {.gcsafe, raises: [CatchableError].} =
   if tx.to.isSome:
     result.to = some(ethAddr(tx.to.get))
@@ -94,7 +94,7 @@ proc unsignedTx*(tx: EthSend, chain: CoreDbRef, defaultNonce: AccountNonce): Tra
   else:
     result.nonce = defaultNonce
 
-  result.payload = tx.data
+  result.payload = tx.payload
 
 template optionalAddress(src, dst: untyped) =
   if src.isSome:
@@ -112,7 +112,7 @@ template optionalBytes(src, dst: untyped) =
   if src.isSome:
     dst = src.get
 
-proc callData*(call: EthCall): RpcCallData {.gcsafe, raises: [].} =
+proc callData*(call: TransactionArgs): RpcCallData {.gcsafe, raises: [].} =
   optionalAddress(call.source, result.source)
   optionalAddress(call.to, result.to)
   optionalGas(call.gas, result.gasLimit)
@@ -160,7 +160,7 @@ proc populateTransactionObject*(tx: Transaction,
   if optionalHeader.isSome:
     let header = optionalHeader.get
     result.blockHash = some(w3Hash header.hash)
-    result.blockNumber = some(w3Qty(header.blockNumber.truncate(uint64)))
+    result.blockNumber = some(w3BlockNumber(header.blockNumber))
 
   result.`from` = w3Addr tx.getSender()
   result.gas = w3Qty(tx.gasLimit)
@@ -191,7 +191,7 @@ proc populateBlockObject*(header: BlockHeader, chain: CoreDbRef, fullTx: bool, i
   let blockHash = header.blockHash
   result = BlockObject()
 
-  result.number = w3Qty(header.blockNumber)
+  result.number = w3BlockNumber(header.blockNumber)
   result.hash = w3Hash blockHash
   result.parentHash = w3Hash header.parentHash
   result.nonce = some(FixedBytes[8] header.nonce)
@@ -206,7 +206,7 @@ proc populateBlockObject*(header: BlockHeader, chain: CoreDbRef, fullTx: bool, i
   result.mixHash = w3Hash header.mixDigest
 
   # discard sizeof(seq[byte]) of extraData and use actual length
-  let size = sizeof(BlockHeader) - sizeof(Blob) + header.extraData.len
+  let size = sizeof(BlockHeader) - sizeof(common.Blob) + header.extraData.len
   result.size = w3Qty(size)
 
   result.gasLimit  = w3Qty(header.gasLimit)
@@ -249,7 +249,7 @@ proc populateReceipt*(receipt: Receipt, gasUsed: GasInt, tx: Transaction,
   result.transactionHash = w3Hash tx.rlpHash
   result.transactionIndex = w3Qty(txIndex)
   result.blockHash = w3Hash header.hash
-  result.blockNumber = w3Qty(header.blockNumber)
+  result.blockNumber = w3BlockNumber(header.blockNumber)
   result.`from` = w3Addr tx.getSender()
   result.to = some(w3Addr tx.destination)
   result.cumulativeGasUsed = w3Qty(receipt.cumulativeGasUsed)
diff --git a/nimbus/tracer.nim b/nimbus/tracer.nim
index d36c1e49c..5658cdd62 100644
--- a/nimbus/tracer.nim
+++ b/nimbus/tracer.nim
@@ -86,7 +86,7 @@ proc dumpMemoryDB*(node: JsonNode, db: CoreDbRef) =
     n[k.toHex(false)] = %v
   node["state"] = n
 
-proc dumpMemoryDB*(node: JsonNode, kvt: TableRef[Blob,Blob]) =
+proc dumpMemoryDB*(node: JsonNode, kvt: TableRef[common.Blob, common.Blob]) =
   var n = newJObject()
   for k, v in kvt:
     n[k.toHex(false)] = %v
diff --git a/nimbus_verified_proxy/rpc/rpc_utils.nim b/nimbus_verified_proxy/rpc/rpc_utils.nim
index c73395396..698c66f37 100644
--- a/nimbus_verified_proxy/rpc/rpc_utils.nim
+++ b/nimbus_verified_proxy/rpc/rpc_utils.nim
@@ -130,7 +130,7 @@ proc asBlockObject*(p: ExecutionData): BlockObject {.raises: [ValueError].} =
   let headerSize = blockHeaderSize(p, txRoot)
   let blockSize = txSize + headerSize
   BlockObject(
-    number: p.blockNumber,
+    number: web3.BlockNumber p.blockNumber,
     hash: p.blockHash,
     parentHash: p.parentHash,
     sha3Uncles: FixedBytes(etypes.EMPTY_UNCLE_HASH.data),
diff --git a/tests/test_rpc.nim b/tests/test_rpc.nim
index ca2593cc4..f642b4799 100644
--- a/tests/test_rpc.nim
+++ b/tests/test_rpc.nim
@@ -383,13 +383,12 @@ proc rpcMain*() =
       check recoveredAddr == signer # verified
 
     test "eth_signTransaction, eth_sendTransaction, eth_sendRawTransaction":
-      var unsignedTx = EthSend(
-        `from`: w3Addr(signer),
+      var unsignedTx = TransactionArgs(
+        `from`: w3Addr(signer).some,
         to: w3Addr(ks2).some,
         gas: w3Qty(100000'u).some,
         gasPrice: none(Quantity),
         value: some 100.u256,
-        data: @[],
         nonce: none(Quantity)
         )
 
@@ -402,7 +401,7 @@ proc rpcMain*() =
       check hashAhex == hashBhex
 
     test "eth_call":
-      var ec = EthCall(
+      var ec = TransactionArgs(
         `from`: w3Addr(signer).some,
         to: w3Addr(ks2).some,
         gas: w3Qty(100000'u).some,
@@ -414,7 +413,7 @@ proc rpcMain*() =
       check res == hexToSeqByte("deadbeef")
 
     test "eth_estimateGas":
-      var ec = EthCall(
+      var ec = TransactionArgs(
         `from`: w3Addr(signer).some,
         to: w3Addr(ks3).some,
         gas: w3Qty(42000'u).some,
@@ -442,14 +441,14 @@ proc rpcMain*() =
     test "eth_getTransactionByHash":
       let res = await client.eth_getTransactionByHash(w3Hash env.txHash)
       check res.isNil.not
-      check res.blockNumber.get() == w3Qty(1'u64)
+      check res.blockNumber.get() == w3BlockNumber(1'u64)
       let res2 = await client.eth_getTransactionByHash(w3Hash env.blockHash)
       check res2.isNil
 
     test "eth_getTransactionByBlockHashAndIndex":
       let res = await client.eth_getTransactionByBlockHashAndIndex(w3Hash env.blockHash, w3Qty(0'u64))
       check res.isNil.not
-      check res.blockNumber.get() == w3Qty(1'u64)
+      check res.blockNumber.get() == w3BlockNumber(1'u64)
 
       let res2 = await client.eth_getTransactionByBlockHashAndIndex(w3Hash env.blockHash, w3Qty(3'u64))
       check res2.isNil
@@ -460,7 +459,7 @@ proc rpcMain*() =
     test "eth_getTransactionByBlockNumberAndIndex":
       let res = await client.eth_getTransactionByBlockNumberAndIndex("latest", w3Qty(1'u64))
       check res.isNil.not
-      check res.blockNumber.get() == w3Qty(1'u64)
+      check res.blockNumber.get() == w3BlockNumber(1'u64)
 
       let res2 = await client.eth_getTransactionByBlockNumberAndIndex("latest", w3Qty(3'u64))
       check res2.isNil
@@ -468,7 +467,7 @@ proc rpcMain*() =
     test "eth_getTransactionReceipt":
       let res = await client.eth_getTransactionReceipt(w3Hash env.txHash)
       check res.isNil.not
-      check res.blockNumber == w3Qty(1'u64)
+      check res.blockNumber == w3BlockNumber(1'u64)
 
       let res2 = await client.eth_getTransactionReceipt(w3Hash env.blockHash)
       check res2.isNil
@@ -476,7 +475,7 @@ proc rpcMain*() =
     test "eth_getUncleByBlockHashAndIndex":
       let res = await client.eth_getUncleByBlockHashAndIndex(w3Hash env.blockHash, w3Qty(0'u64))
       check res.isNil.not
-      check res.number == w3Qty(1'u64)
+      check res.number == w3BlockNumber(1'u64)
 
       let res2 = await client.eth_getUncleByBlockHashAndIndex(w3Hash env.blockHash, w3Qty(1'u64))
       check res2.isNil
@@ -487,7 +486,7 @@ proc rpcMain*() =
     test "eth_getUncleByBlockNumberAndIndex":
       let res = await client.eth_getUncleByBlockNumberAndIndex("latest", w3Qty(0'u64))
       check res.isNil.not
-      check res.number == w3Qty(1'u64)
+      check res.number == w3BlockNumber(1'u64)
 
       let res2 = await client.eth_getUncleByBlockNumberAndIndex("latest", w3Qty(1'u64))
       check res2.isNil
diff --git a/vendor/nim-ssz-serialization b/vendor/nim-ssz-serialization
index aa8f487de..fe033e257 160000
--- a/vendor/nim-ssz-serialization
+++ b/vendor/nim-ssz-serialization
@@ -1 +1 @@
-Subproject commit aa8f487debbe5c0b7c49951d2b668beb394d9c01
+Subproject commit fe033e257af5ff1188f92e295eabd33da6459fc5
diff --git a/vendor/nim-web3 b/vendor/nim-web3
index 428c46c94..285d97c2b 160000
--- a/vendor/nim-web3
+++ b/vendor/nim-web3
@@ -1 +1 @@
-Subproject commit 428c46c94f58cf19d052b25cd3ae6f4c8c722e56
+Subproject commit 285d97c2b05bbe2a13dab4b52ea878157fb1a1a1
diff --git a/vendor/nimbus-eth2 b/vendor/nimbus-eth2
index 386337357..1fe6efcf5 160000
--- a/vendor/nimbus-eth2
+++ b/vendor/nimbus-eth2
@@ -1 +1 @@
-Subproject commit 3863373575c89e172a734ba71cf516c572288a54
+Subproject commit 1fe6efcf53d419b56f6fbf1e21289171017cad15