543 0R 505

It must not be a big deal. I bought these pistons off Jason Digby owner of the one time fastest car on leaf springs. He was running a nitrous combo then going I think 4.40’s. I bought them when he switched to a turbo.
Dude with the black & red stripe 69 dart ?
Predator engine ? Lol, I just looked it up, the cars called tooth jerker because hes a dentist.