i pieced together a motor a few years ago that was 4.125 bore 350 010 block for my modified. It ran about 220*-230* which wasnt too bad. I did have concrete in it up to the bottom of the soft plugs. I ran that motor for 10 or 15 races and sold it to a guy from missouri who also came to by an old frame from me as well, never talked to the guy since so dont know if he ran it or not.