Oil and water mixing
 

I have a 351W punched to 396 w/ World Products heads. I have oil in water and water in oil. Came from nowhere. Replaced head and intake gaskets and same problem. Had heads checked, checked block valley and no problems found. Any thoughts or help before I pull the engine? Thanks to all who respond..........Karl

Re: Oil and water mixing
 

well cracked heads can do that but u said u had them checked.did you over heat it?does it smoke?does it run ok?how fast are you loosing coolant?you could have a cracked block.possiable to have a cracked timing chain cover or timing chain cover gasket leaking internally but not likely