500+ci Builder

I don't know of any 4.25 stroke packages that will be able to use a stock rod. They use smaller rod pin and wrist pin sizes, and the beams and bolt/nut fasteners would require a ton of clearancing and possibly an external oil line and pickup. I know the 496 (4.25 B) I have now couldn't use factory rods. Even if the crank was the B rod journal they'd hit the bores and the oil pickup boss would have to be removed almost entirely. Same with the 505 (4.25 RB).