is the 10 bolt 8 3/4 inch the same as the 10 bolt 8 1/2 inch that is the 3rd member not the ring gear 4 or 5 years ago i got a posi 3rd member used for my 81 step side and never instaled it because i wanted to switch to disk brakes at the same time and because i didn't need a brake job and the if its not broke don't fix it... now when i readt to do it i think it is the rong one. bob
