i know i ran 501" in. 533 ex. against a set of bone stock heads for a while. i would assume you would be fine with your selection with your mods. also the stock bottom ends are a lot stronger than i ever gave them credit for with 8 ton of block on a trailer behind me a couple wild downshifts i saw 8000 rpm before i heard the pop. crank is still good rods are fine but the valve train didn't survive. well good luck and beyond all don't get mad cause ya didn't win be happy cause you were able to try