If I recall correctly my old 7 ¼ backing plate had 4 mounting holes and the 8 ¼ backing plate had 5 holes (like my 8 ¾). It was some time ago when I put the bigger Rear end in the Barracuda but I remember there was problem with using the 7 ¼ backing plates. I also got rid of the V shaped parking brake cable that runs down the middle of the car and used one that routed down the side and over the rear end.
