If your finished bore is right for the pistons you have and your rings are not file fit I think you would have no problem with sticking them in the way they are.kkc65p said:They are cast aluminum flat top pistons. Stock for the 425. A stock ring replacement kit. The motor is a 350 block bored to fit the 425 piston. Block has been decked .010 and the heads have been shaved. This motor is being used in a dirt track race car (pure stock division) at the local race track. Max rpm is 4500 to 5000 at any given time on the track.