Fully torn down and no issues found?! I noticed a chatter mark from a drill on the sealing area of #1 so I sejt the head back to APE for another round of milling. #2 (the offending cylinder) has perfect sealing valves as per APEs vacuum testing. So, no gasket failure, no lower end failure, no top end failure...wtf! It'll be together next week and heat cycled a few times, then boosted. We'll see. I have to guess it maybe wasnt torqued correctly? Who knows? Whatever it was, it wasn't my parts or my doing.