Ok I've had an uoa done just to check on things, shows coolant in oil the thing is car runs great, has great oil pressure at idle and wot,doesnt over heat and oil looks like clean new oil. have done exhaust gas test in radiator and checked out fine, but it does lose pressure with pressure tester and coolant does go a alittle low about 2 to 3 inches from top of radiator, no external leaks. I am having heads pulled what would you think the chances are of a cracked block or heads. does this happen often or do you think a head gasket would be the problem, just worried about finding bad block or head with these symptoms. mods are in sig

 

probably a blown head gasket. time for a cleanup mill and some stock MLS gaskets.

 

^x2...oil radiator in oil is sure sign of head gasket failure, when there are no external leaks present.

clean up those pistons and cylinder walls with some carb cleaner and a rag while you are at it.