[72blackbird]

I don't remember if GM stamped STD on the factory slugs, but if if you see L2262F stamped on them you're looking at a set of TRW forged pistons. These used to be about $200/set, but have risen in price to about $340/set now.

If the the bore has less than .001" taper from bottom to top, you could reuse the pistons to save money. I would only recommend cast pistons for a bone stock application- like the factory rods, they will only withstand standard loading. If you're planning to do any type of racing, use forged pistons and rods- the factory parts will fail in extended high rpm use.

Geno