diff --git a/.spectest_version b/.spectest_version
index 18fa8e74f..0a7905b0e 100644
--- a/.spectest_version
+++ b/.spectest_version
@@ -1 +1 @@
-v1.3.0
+v1.4.0-alpha.0
diff --git a/lib/lambda_ethereum_consensus/state_transition/operations.ex b/lib/lambda_ethereum_consensus/state_transition/operations.ex
index acf8e5a72..f45788fcb 100644
--- a/lib/lambda_ethereum_consensus/state_transition/operations.ex
+++ b/lib/lambda_ethereum_consensus/state_transition/operations.ex
@@ -3,7 +3,6 @@ defmodule LambdaEthereumConsensus.StateTransition.Operations do
   This module contains functions for handling state transition
   """
 
-  alias LambdaEthereumConsensus.Engine
   alias LambdaEthereumConsensus.StateTransition.{Accessors, Misc, Mutators, Predicates}
   alias LambdaEthereumConsensus.Utils.BitVector
   alias SszTypes.BeaconBlockBody
@@ -242,14 +241,13 @@ defmodule LambdaEthereumConsensus.StateTransition.Operations do
   @doc """
   State transition function managing the processing & validation of the `ExecutionPayload`
   """
-  @spec process_execution_payload(BeaconState.t(), ExecutionPayload.t(), boolean()) ::
+  @spec process_execution_payload(BeaconState.t(), BeaconBlockBody.t(), fun()) ::
           {:ok, BeaconState.t()} | {:error, String.t()}
-
-  def process_execution_payload(_state, _payload, false) do
-    {:error, "Invalid execution payload"}
-  end
-
-  def process_execution_payload(state, payload, _execution_valid) do
+  def process_execution_payload(
+        state,
+        %BeaconBlockBody{execution_payload: payload},
+        verify_and_notify_new_payload
+      ) do
     cond do
       # Verify consistency of the parent hash with respect to the previous execution payload header
       SszTypes.BeaconState.is_merge_transition_complete(state) and
@@ -265,7 +263,7 @@ defmodule LambdaEthereumConsensus.StateTransition.Operations do
         {:error, "Timestamp verification failed"}
 
       # Verify the execution payload is valid if not mocked
-      Engine.Execution.verify_and_notify_new_payload(payload) != {:ok, true} ->
+      verify_and_notify_new_payload.(payload) != {:ok, true} ->
         {:error, "Invalid execution payload"}
 
       # Cache execution payload header
diff --git a/lib/lambda_ethereum_consensus/state_transition/state_transition.ex b/lib/lambda_ethereum_consensus/state_transition/state_transition.ex
index 2b1044304..81fb02f04 100644
--- a/lib/lambda_ethereum_consensus/state_transition/state_transition.ex
+++ b/lib/lambda_ethereum_consensus/state_transition/state_transition.ex
@@ -3,6 +3,7 @@ defmodule LambdaEthereumConsensus.StateTransition do
   State transition logic.
   """
 
+  alias LambdaEthereumConsensus.Engine.Execution
   alias LambdaEthereumConsensus.StateTransition
   alias LambdaEthereumConsensus.StateTransition.{EpochProcessing, Operations}
   alias SszTypes.{BeaconBlockHeader, BeaconState, SignedBeaconBlock}
@@ -117,10 +118,12 @@ defmodule LambdaEthereumConsensus.StateTransition do
 
   # TODO: uncomment when implemented
   def process_block(state, block) do
+    verify_and_notify_new_payload = &Execution.verify_and_notify_new_payload/1
+
     {:ok, state}
     |> map(&Operations.process_block_header(&1, block))
     |> map(&Operations.process_withdrawals(&1, block.body.execution_payload))
-    # |> map(&Operations.process_execution_payload(&1, block.body, EXECUTION_ENGINE))
+    |> map(&Operations.process_execution_payload(&1, block.body, verify_and_notify_new_payload))
     |> map(&Operations.process_randao(&1, block.body))
     |> map(&Operations.process_eth1_data(&1, block.body))
     # |> map(&Operations.process_operations(&1, block.body))
diff --git a/lib/spec/runners/operations.ex b/lib/spec/runners/operations.ex
index c962e5f12..cfcf29ab7 100644
--- a/lib/spec/runners/operations.ex
+++ b/lib/spec/runners/operations.ex
@@ -2,9 +2,12 @@ defmodule OperationsTestRunner do
   @moduledoc """
   Runner for Operations test cases. See: https://github.com/ethereum/consensus-specs/tree/dev/tests/formats/operations
   """
+
   alias LambdaEthereumConsensus.StateTransition.Operations
   alias LambdaEthereumConsensus.Utils.Diff
 
+  alias SszTypes.BeaconBlockBody
+
   use ExUnit.CaseTemplate
   use TestRunner
 
@@ -17,7 +20,7 @@ defmodule OperationsTestRunner do
     "proposer_slashing" => "ProposerSlashing",
     "voluntary_exit" => "SignedVoluntaryExit",
     "sync_aggregate" => "SyncAggregate",
-    "execution_payload" => "ExecutionPayload",
+    "execution_payload" => "BeaconBlockBody",
     "withdrawals" => "ExecutionPayload",
     "bls_to_execution_change" => "SignedBLSToExecutionChange"
     # "deposit_receipt" => "DepositReceipt" Not yet implemented
@@ -32,7 +35,7 @@ defmodule OperationsTestRunner do
     "proposer_slashing" => "proposer_slashing",
     "voluntary_exit" => "voluntary_exit",
     "sync_aggregate" => "sync_aggregate",
-    "execution_payload" => "execution_payload",
+    "execution_payload" => "body",
     "withdrawals" => "execution_payload",
     "bls_to_execution_change" => "address_change"
     # "deposit_receipt" => "deposit_receipt" Not yet implemented
@@ -53,13 +56,9 @@ defmodule OperationsTestRunner do
     # "bls_to_execution_change"
   ]
 
-  @disabled_cases [
-    "bad_parent_hash_first_payload"
-  ]
-
   @impl TestRunner
-  def skip?(%SpecTestCase{fork: "capella", handler: handler, case: testcase}) do
-    Enum.member?(@disabled_handlers, handler) or Enum.member?(@disabled_cases, testcase)
+  def skip?(%SpecTestCase{fork: "capella", handler: handler}) do
+    Enum.member?(@disabled_handlers, handler)
   end
 
   @impl TestRunner
@@ -93,19 +92,21 @@ defmodule OperationsTestRunner do
     handle_case(testcase.handler, pre, operation, post, case_dir)
   end
 
-  defp handle_case("execution_payload", pre, operation, post, case_dir) do
+  defp handle_case("execution_payload", pre, %BeaconBlockBody{} = body, post, case_dir) do
     %{execution_valid: execution_valid} =
       YamlElixir.read_from_file!(case_dir <> "/execution.yaml")
       |> SpecTestUtils.sanitize_yaml()
 
-    result = Operations.process_execution_payload(pre, operation, execution_valid)
+    result =
+      Operations.process_execution_payload(pre, body, fn _payload -> {:ok, execution_valid} end)
 
-    case result do
-      {:ok, state} ->
-        assert Diff.diff(state, post) == :unchanged
+    case post do
+      nil ->
+        assert {:error, _error_msg} = result
 
-      {:error, error} ->
-        assert post == nil, "Execution payload failed, error: #{error}"
+      post ->
+        assert {:ok, state} = result
+        assert Diff.diff(state, post) == :unchanged
     end
   end