Inliners International Forums General Discussion Hi Performance who has .040 over propane pistons 292

As others have said, depends on the cam. I am running a 219@.50 cam and "theoretically" can run over 10:1 compression with 93 octane. I settled on 9 3/4:1 and achieved that between pistons, decking the head and the block. My logic was better to be slightly low on compression than slightly high.