i have a 8 3\4 rear and changing to big bolt pattern and looking for brake parts for the swap. Are all bbp backing the same other than brake diameter? Is there different backing plates for the different widths? Will 1\2 ton parts work or do they need to be for a car? Any specific model? Any to avoid? Is there a place to buy new?
Changing to BBP. Brake questions
- Thread starter 66signet
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4mulas
Fixem'up
You can use dodge diplomat or Chrysler fifth ave backing plates and they should be around at your local junkyard.
Yeah but the parking brake cable area attaches differently.
You MUST match the backing plates to the brake width. I think there are 3 different offsets? For instance if you want 10" X 2-1/2" rear brakes, you need the backing plates for that combo. My personal opinion is 11" drums add a LOT of weight and not necessary on an A-body. It'll actuallly slow your car down with all that additional rotational mass.
Relying on my memory here....I believe late in the A-body run, the brakes went to 10 X 2-1/2" so that's a good source. (Look at 4 doors)These were on the 8-1/4 rear but they fit the 8-3/4". 7-1/4 bolt pattern is different.
My own personal experience; I used late 60's B-body backing plates, shortened and resplined C-body axles and went with 10 X 2-1/2 brakes. Bought hardware, shoes and new drums. The parking brake cable was a direct fit. This adds 3/8" to the track on each side.
I just happened to have a rear wheel off.
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jos51700
Green Bearing thread connoisseur
I just took the rear brakes on an FMJ car, backing plate and all, and plopped it on my axle. So long as your axles are offset for the later brakes, it's a no-brainer, and no mishmash parts crap to deal with down the road. Number stamp FMJ in the backing plate (or whatever you get them off of) and circle with a paint marker, and 20 years from now it'll be easy.
This is why I favor BBP swaps via swapping the axles, vs re-drilling drums (wear components) and axles.
This is why I favor BBP swaps via swapping the axles, vs re-drilling drums (wear components) and axles.
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4mulas
Fixem'up
Almost all later 73 and up A body with disc brakes and also earlier b - e 10” brakes are 10x2.5”. As well as diplomat, volare, aspen, New Yorker, 5th avenue, and some smaller truck brakes too
when you get the backing plates also take the spreader bars and maybe even the e brake levers. Don’t listen or to or worry about a different post previously here saying the cables attach differently. They don’t.
‘it’s an easy conversion
when you get the backing plates also take the spreader bars and maybe even the e brake levers. Don’t listen or to or worry about a different post previously here saying the cables attach differently. They don’t.
‘it’s an easy conversion
I have a 68 d100 and a 70 here and they are both 8 3\4 rears I could get brake parts from. The wrecking yards where I'm at are closing. They are still towing and have cars in the yard but they're not selling parts. There is a yard only about a block from my house. They open at 8:00 and lose at 4-5:00 and I work 6:30 til 6-7:00. I have been watching here and eBay and market place looking for parts or even a car I could buy to get the parts from and sell off the rest but haven't found anything yet. Will all bbp swaps add track width? If so when I buy wheels I will need a different offset.
cudamark
Well-Known Member
Some of the larger brakes are not recommended because some of the components are getting hard to find. I'd avoid the B-body 10 X 1 3/4" and truck/C-body 11 X 2" brakes for sure. For a typical A-body, the 10 X 2 1/2" brakes found on many, many models would be my choice. If you really have to have bigger brakes, the 11 X 2 1/2" would be fine too. The 11 X 3" will also work, but, are not near as common to find. As mentioned, get a matched set.....as in all the hardware, shoes, drums, adjusters, spreader bar, E-brake lever, etc, that match the backing plates.
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