[juliosz]

You may want to check to see if it has the stock bore. I bought a set of .020 over 302 pistons from a friend that he got at Smokey's garage sale (he bought several sets). The set I bought has stock size ring lands but he also had a few sets that had really thin ring lands. I can't remember the GM part number but it was stamped into the dome of each piston. I would vote for at least disassembling and checking that everything is ok.