I have a choice of putting a 14 bolt FF rear under my '81 Suburban with the 13" drums or the smaller 10" (or 11"?) drums. I'm under the impression that the 13" drums add more weight, but also have greater braking ability. I also know that the smaller drum rear I have has new brakes and the 13" drum rear is unknown (as far as brake cond.) Which should I use?