Perhaps you can make a 4.75 stroke fit with aluminum rods and a 2.200 pin size, but you would need to take a lot off in a crtical area of the rod, IMO. And the question was, is it worth it for 572-13 heads? I would say no, and it would add a lot of expense for very little gain. As I started to say, you can do anything you are willing to pay for, but the expense involved is not worth it. If you want a high horsepower 1100+ combo, contact Pete at Best or Diablo. They have proven combos for sale, and that's not as easy to do as some people try to make it sound, at least not naturally asprirated.