Did Mopar ever actually use the same 10 X 1 3/4" rear drum brakes on a 7 1/4" rear end as on the 8 3/4" rear end? Here's the deal.....I just yanked out my old wimpy 7 1/4" rear end and installed an 8 3/4".....I installed the correct (and all rebuilt) backing plates from an A-body. I thought I...