I just ordered my BBP Moser axles ... i will remove exisiting SBP Moser axles .. install volare 10X 2.5 backing plates and hardware.. install new BB Moser axles and order my volare bbp drums .. i will let you know results ... thanks for input
A lot of information to digest. I am beginning my build so let me make sure I have this right. I want to go to BBP just for the better options of wheels. For the front my option is to swap the front spindles, rotors and upper A arms from a 73-76 B body? that would have to include master cylinder and proportioning valve? which while I'm there I might as well get the booster (did I miss anything, like linkage)? Now for the rear I can use the axle from the same car but I need to relocate the spring mounts 1/2 inch inboard? If I just want to swap axle shafts I have to drill the drums for BBP? I can't swap drums and backing plates from the donor car and install BBP axles unless I use the axle housing from the donor car, right?
The UCA's have to come from a 73-76 A body equipped with disc brakes? Do all these models have the BBP?
I assume that the spindles, rotors and calipers must come from the same A body?
Do all 73-76 A bodies use the 15/16" master cylinder? What other models should I be looking at?
Why don't you like power brakes on these cars?
As for the rear of the car, any suggestions? I would like to come out with a larger diameter drum in the process.
Thanks so much for the information. Currently the car has a 7 1/4 rear axle with 3.23 ratio. The drums measure 11" though, does that sound right?
I was trying to measure the brakes from the ground under the car. Again thanks for the information. I haven't had any luck finding a salvage yard with pre-90's anything.
Please let me know if my research is correct for the rear end. To install a 8 3/4 my options are:
Find a 8 3/4 from a 65-72 A body then change the axle shafts to BBP and either drill the drums or change backing plates and drums from BBP car.
Find a 62-70 B body rear end and move the spring perch in 1/2" which will require new perch with 1/2" locating pin hole.
Are these my options?
Assuming that you're buying a set of BBP axles that will work.
Also recall that 11" rear drums came in 11x2, 11x2.5, and 11x3" varieties, and you can't swap drums and backing plates with those either. Since the BBP axle offset was the same for all of them, the axle flange is in the same place for all of those and therefore the offset for the backing plates on each of the 11" drum set ups was different. Meaning, if you have 11x2" backing plates, you can't just buy 11x2.5" drums and shoes and run those. Somewhere I have those measurements to tell which is which.
***Edit***
Found the measurements.
To measure the backing plate offset you want to set the backing plate flat on a bench. You'll need to hang the bottom 1/3 of the backing plate off the edge of the bench so that the mounts for the e-brake cables don't keep the backing plate from sitting flat. It isn't much, but they do change the measurement. Then, measure from the bench to the top of the backing plate through the center hole (for the axle) in the backing plate.
If you get ~1.75", you have 11x2.5" plates. If you get ~1.5", you have 11x2" plates. Those I know for sure, as I've measured them. I don't have a set of 11x3" backing plates, but the math would say you'd get ~2" measuring them as I described above. This is because half of the additional width is on the inside of the axle flange and the other half is on the outside to keep the axle flange in the same spot, as there was only one axle offset for BBP 8 3/4 axles.
View attachment 1715019208
Also, if you have a set of 10" backing plates without any hardware, shoes etc you can measure those to determine if they're BBP 10" backing plates or SBP 10" backing plates. BBP plates will measure 1.75", they're 10x2.5" and have the same axle flange offset as the 11x2.5" brakes so you get the same measurement. The SBP 10" backing plates will measure roughly 1.25"