I had my B body 8 3/4 narrowed one inch less than the stock A body where which is what your using, I think I used Welds that had one inch negative, one inch less offset on the inside than the width of the wheels, 10 inch wide with 4.0 inch inset on the inside, 5 inch on the 12 inch wide rims Maybe they where 4.5 and 5.5