318 compression ratio

You are correct (not that you needed me to tell you that). The guy told me that indeed the heads were milled to achieve a zero deck piston. How much exactly was milled he didn't know because he bought the engine in a Coronet and swapped out engines. So the guy before him had the work done. Between the fast burn heads and the mill work done on them, I'm assuming the compression ratio wouild be substantially greater then the factory 8.6 to 1. But without knowing how much was milled, I guess we can't know for certain.