Difference in drum brakes A-B Body

340butterduster said

It doesn't matter what body style the drums came from. The backing plates are different from 1 3/4" to 2 1/2" drums, the bolt pattern you already know.
The offset is built into the backing plate.
There is also differences in drum diameters, 10"-11".


My understanding ( I haven't tried this) that backing plates from 8 1/4" will also bolt in.

Hope this helps.

Click to expand...

Ohhh Ok...So the actual overall length of the axle and wheel mounting surface doesn't change. The backspace of the backing plates change. Thanks for clearing that up for me.

As for the 10" or 11" brakes, it doesn't really matter to me which ones I use as long as they are the 2 1/2" pads, and large bolt pattern, so they will go on the B body 8 3/4 I'm getting.

So, now my mission is to find a donor car that has a drum brake setup I can snag off of it...:)

-OR- Couldn't I just use the small bolt pattern 1 3/4" brakes that came off my A body 8 3/4 and just have the drums redrilled?