Chevy parts mostly big block.
Set of 8 Big Block High Compression Chevy pistons 3963551 and dimple rods. The rods are 6.135 in length with 7/16 hardened bolts. GM and TRW cast into the bottom inside. They appear to be 12.4-1 open chamber pistons? So far have only looked at 1 out of the 8.