The JE Pistons are the ones most everyone has gone with. Wiseco also makes some that are 8.5:1 as well. the one's HRC sells and uses are JE pistons. you can also go to www.raceeng.com for these pistons and for rods as well. That's where I got mine. They have a good price and are a godd shop located in Florida. The 1st gen rods you mention are for the 4G63 and not the 420A. We are the 1st gen 420A
