I have not called piston mfg. yet but was wondering what the ring gap should be for a 72.5mm piston. I got no paperwork with piston. I'm ready to put it in today but the only thing I still need to know is the ring gap. A buddy said he has never filed his rings, they always fit. I want to know hard numbers, I think I heard on this sit that .013 is a good all around gap number but not sure. Please help, wanna get this thing running.