Did the exhaust/intake manifold gasket. Unfortunately I didn't have this thought until after the fact...
This doesn't sound like an exhaust manifold leak. It sounds like an header blown gasket or worse warped head.
It sounds like a very loud, numbing almost lawn mower.
I'm about to start working on getting the head off. So the question now is what is the likely hood of it being warped verses blown gasket?
Little details, did a compression test and 1-5 were great, number 6 is 40 psi. There is no water in the oil and no oil in the water.
Any help would be appreciated.