Boy does this thread look familiar. Have you rebuilt the engine or had it apart? If so, check the torque on the head bolts. Mine was a combination of wrong timing and a bad torque wrench. Figured it out after the third set of head gaskets.
1953 Chevrolet 3600 Fried Green T'mater (Vern) In the Stovebolt Gallery Caution: Political Statement Man who runs in front of car gets tired, man who runs behind car gets exhausted.