don't waste your money on custom pistons, I built plenty of engines with cast pistons and never an issue with a mostly street car, My last poncho 350 was an ho engine last year only issue was the ho pistons are not available so I just used the 2 barrel .030 piston and took .020 off the deck. cast pistons have no problem under 6000 rpm thats what the oem used. Dont get too wound on the pistons, make sure you have a good machinist that's more important, one thing I would suggest if your rods need to be reworked probably cheaper to buy a new set stronger than the factory and a bit cheaper than getting yours reworked.