I use wiseco off the shelf 13.7 pistons in my motor now. But I have a drag cartel custom set of je pistons for another motor. Wiseco is a little heavy they weigh bout 342 grams. If u looking for a 12.5 piston get a cp. They are pretty good from what I hear. I have a few friends who run those wit no complaints. I guess its builder preference on what piston they use.