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.
Sorry, but I just can't let this go.
(1) There were no such thing as 350HO pistons. All the Pontiac 350 pistons were the same, up thru about '73. They were cast & had 4 small valve reliefs. '74-'77 350 pistons had flat tops with no valve reliefs at all. If you have any verifiable proof that I'm wrong, please post your info.
(2) The cheapest forged Pontiac rods are now nearly $400 shipped.
Guessing that even with the new ARP rod bolts, which are less than $65, you can get a set of rods resized for $250 or less. If you've paid more than $400 to have some cast rods resized, please post this info, along with contact info for the shop that charged that much.
