1974 Scamp - Swapping 7 1/4 to 8 3/4 Questions
1- Yes, you can use the brakes from your BBP 7.25 on your 8 3/4. All of the BBP brakes and axles use the same axle flange offset. The backing plate might only have 4 holes on the 7.25, but drilling the 5th hole (if it isn't already there) is all you need to do.
2- I run AFCO 20231M's. They're a 121 lb/in spring that's been discontinued. I use spring sliders in the back that lowered the car about 3/8" from there. The AFCO's use the factory arch, although if anything I'll probably add 1/2" lowering blocks
3- You would not want to use 0° for the pinion angle. The factory pinion-to-perch angle for an A-body 8 3/4 is 5° up, which with the factory springs/ride height/driveline angles gives about a 2° down pinion angle. Also, IIRC the B-body perch angle was not the same as the A-body perch angle, so don't copy that either.
1- Yes, you can use the brakes from your BBP 7.25 on your 8 3/4. All of the BBP brakes and axles use the same axle flange offset. The backing plate might only have 4 holes on the 7.25, but drilling the 5th hole (if it isn't already there) is all you need to do.
2- I run AFCO 20231M's. They're a 121 lb/in spring that's been discontinued. I use spring sliders in the back that lowered the car about 3/8" from there. The AFCO's use the factory arch, although if anything I'll probably add 1/2" lowering blocks
3- You would not want to use 0° for the pinion angle. The factory pinion-to-perch angle for an A-body 8 3/4 is 5° up, which with the factory springs/ride height/driveline angles gives about a 2° down pinion angle. Also, IIRC the B-body perch angle was not the same as the A-body perch angle, so don't copy that either.