I have a set new forged popups with solid dome, meaning make them flat tops or a little more if you like, these std. bore 283 sbc, cheap way to make a .075 over 312 for the guys with .060 blocks, takes a .927 common pin, they are floaters . Back in the day ,the stock car guys do this all the time. These are as nice a piston around, takes std 283 rings thats a plus. Pin ht. is close, I forget exactly. some where along the line, there is 2 mismatched pins 
Did not ebay these for the chevy nuts. I want $225 , call me at 931-739-0152