Well FACK it blew again today: Its always from BIG throttle to off throttle: Solved the
oil leak and now back off again (i am getting quick at it): My confidenc in this motor is quickly dwindling to zero...need to check the manifold and heads for flatness, and use the best gaskets i can i guess: Its a small block making a crap load of power...
One thing i am wondering about is tapping into the back coolant passages and plumbing them back to a return? Seems weird having a stagnant passage back there? i would suspect that the cause is likely a big sudden vacuum spike off throttle at high rpm...
Gonna do some research before bolting this ***** back together yet once again...