B body rear axle in an A body
Seems like everybody's nailed it so far. B-body 8 3/4 in a Duster is a pretty good swap, especially if you want to run larger diameter wheels (17/18) because they generally have the backspace you need right off the shelf. Stock perches on a B-body are 44" center to center, so you will need to move the perches to 43" for use in an A-body with the stock spring locations.
It does matter which B-body rear end you use, because there are different widths. You can see that here, and compare to the A-body width. The perch location also changed for the '71+ cars.
8 3/4" Rear end widths, drum-to-drum:
A-BODY
Before I did the disks and larger wheels I was running 15x7's with a 4.25" backspace, I had 225/60/15's on those but that was about all the room I had to the uncut quarter lips. If you wanted to run wider tires than that on the 68-70 B rear you'd need more backspace. A 15x6" seems really small, especially on a Duster. Those little guys will get lost in the wheel wells. Even the 15x7's with 225's looked tiny on my car.
Keep in mind that a Duster has an entire extra inch of room to work with to the quarter lip compared to a Dart. Springs and frame rails are in the same place, but the Dusters/Demons/Dart Sports have wider quarter panels and outer wheelhouses.
Seems like everybody's nailed it so far. B-body 8 3/4 in a Duster is a pretty good swap, especially if you want to run larger diameter wheels (17/18) because they generally have the backspace you need right off the shelf. Stock perches on a B-body are 44" center to center, so you will need to move the perches to 43" for use in an A-body with the stock spring locations.
It does matter which B-body rear end you use, because there are different widths. You can see that here, and compare to the A-body width. The perch location also changed for the '71+ cars.
8 3/4" Rear end widths, drum-to-drum:
A-BODY
- '66-'72= 57 1/8” (or 57 13/16” for BBP axles and brakes)
- BBP 8.25/7.25= 56 3/4”
- '62-'63= 58 1/2" (And '64 Max Wedge)
- '64 = 60 7/8" (Exc.Max Wedge)
- '65-'67= 59 1/2"
- '68-'70= 60 1/8"
- '71-'74= 63"
- '71-'73 wagon= 64 3/8"
Before I did the disks and larger wheels I was running 15x7's with a 4.25" backspace, I had 225/60/15's on those but that was about all the room I had to the uncut quarter lips. If you wanted to run wider tires than that on the 68-70 B rear you'd need more backspace. A 15x6" seems really small, especially on a Duster. Those little guys will get lost in the wheel wells. Even the 15x7's with 225's looked tiny on my car.
Keep in mind that a Duster has an entire extra inch of room to work with to the quarter lip compared to a Dart. Springs and frame rails are in the same place, but the Dusters/Demons/Dart Sports have wider quarter panels and outer wheelhouses.
