I have a GM 1946 dealer built flatbed that is exactly 8 feet wide. Keep in mind however that your rearend setup sounds like it is several inches narrower than stock. I think I measured about 90 inches with tire on mine if I remember right. The 8 foot bed gives me about a 3 inch overhang on each side which looks very nice considering tire size and everything. Also consider how high off the rear wheels your bed will be. If it sits close to the tires it will look better narrower. As it moves up off the tire, IMO you need a little more overhang to get the same look.
