They are Speed-Pro forgings, weigh a ton and I'd measure the dinged-up one and use it if there was no noticeable distortion at the piston crown diameter.

Or go to any parts store or Summit/Jegs and buy a single, they're still in production.

This is my place to say they weigh a ton and there are better pistons out there from a weight point of view. But since you have them go for it.

R.