After waiting a few centuries, amazon and ebay sent me my parts to do a rebuild on my top end, but as the title suggests, I can not do so. the new piston, pinon and bearing are too small in diameter compaired to the old one and would knock severly in the connecting rod. The old piston had a chunk fly off it and out my exhaust so clearly the old one cant be used. Tomorrow I was planning to go to a machine shop if any were open, to see if they can make a filler piece or bushing of sorts out of the old pinion so I can use the old bearing with the new pinion and piston. but if anyone else has any better ideas I would love to hear it. Thanks.