1970-73 Challenger rear Backing plates

ronw said
Do both the 10" and 11" take the same backing plate? And what is the width of the shoes?

No they don’t. That’s why I said that the outer diameter of the backing plate could be measured to determine the brake size. The backing plate diameter is 1” larger than the drum that fits it.

If you have backing plates for 10” brakes and they’re E-body the shoes are 10x2.5”. If you have backing plates for 11” brakes you’ll have to measure the backing plate offset, because there are 3 different shoe widths for the BBP 11” drums.

krazykuda said
The parking brakes strut lever on the 10" brakes is different between A body and e-body...

The a-body has a bend in it to accomodate the narrower shoes, where the e-body lever is flat....

I'm not sure about the backing plates...

The other thought that comes to mind is can you put an e-body set-up on an a-body??? If the strut plate lever is flat for the e-bodies does will it fit on an a-body??? I have never compared the dimension from the backing plate to the back of the flange on the axle to see if it is different between the two bodies... If the flange to backing plate clearance is different, they you may not be able to put e-body brakes on the a-body...

Strut levers:

A-body:

View attachment 1716176253

B/E-body:

View attachment 1716176254

He has E body backing plates, at least according to his first post.

And he has an E-body 8 3/4, which were all 5x4.5”, so none of the brakes will work with an A-body 8 3/4 unless he uses BBP axles with the BBP axle flange offset.

SBP A body brakes have a different backing plate offset, shoe width, drum depth etc and since he’s got E-body stuff there’s really no need to muddy the water further with A-body brake info