It would be a 2 ton, and it would have had a 265 V8 with an SM420 trans originally. The front track width is 63.74", with overall width at the fenders is 80".
Unless the original frame is damaged, I really can't see a reason to replace it. If the spring pads line up and the track width is ok, you may consider installing the IH axles to the Chevy frame. That'll preserve the body to frame relationship by keeping the cab on the mounts it was designed to fit.
