So I’m really new to mopar engines, so please forgive my ignorance. I have a 1970 tucker snowcat with a 318 industrial engine. I recently replaced the old tired engine with a newer 318 block with rv cam. Purchased from a local engine builder. I put it all back together and fired it up, however found water in the oil I immediately thought it was a cracked head. I also found coolant in the #1 cylinder. I pressure tested the number one cylinder and it tested fine. I’m now thinking it my be the intake manifold. Does any body know if the industrial motor has a different intake that maybe doesn’t fit correctly? It did look ok, but like I said I’m definitely new to mopars. Please chime in as to where you think the coolant could be leaking from.

 

Compression was good when you checked it ?
What happened when you pressured checked the cooling system and left the number one spark plug out? Did water run out?