What EXACTLY do you mean by losing compression??????head gasket leaking? valve leaking? cracks??


If your on a low $ budjet rebuild, have vales/seats refaced,maybe resurface deck surface---put it together and drive it---


Maybe post the casting numbers here and some pics of the piston or complete info as to numbers/manufacturer---seems like there's quite a difference in what you have compared to what you think you have----IE---you won't get a 454 piston into a 396 bore--------