Yeah, but I don't exactly have a few heads laying around to practice milling it down, and this being my only motor, I don't want to run the risk of permanently damaging the head and jug. Also, at TDC, the edge of the piston sits pretty much right at the top of the cylinder, so I'm sure if I try milling the jug down, I will also wind up damaging the piston head. My best bet is using a pre-made gasket or make one that is extra thick and can squish down quite a bit. Also, is the inner edge of the gasket supposed to hang slightly over the cylinder wall, or is it supposed to be flush with it?