B-Body Axle?
I have a 72 dart 7 1/4 rear and want to use a 66 charger 83/4 I can move spring perches and what ever else needs to be done without narrowing the rear. has anyone done this swap? and if so what did you do for rims and tires? it will be about1 3/8" wider per side
The '66 Charger 8 3/4 rear should be 1-3/16" wider per side, that accounts for the width of the axle and the wider BBP brakes.
You shouldn't have any issues moving the perches in and using that axle. All it means is that you'll need to add more backspace to the rims you use, to the tune of 1-3/16". So, instead of a 15x8 with 4.5" of backspace, you'll need about 5.7" to 6" backspace. If you wanted to use 17 or 18" rims, it would be a piece of cake, because you could use Mustang rims. 17x8 with 5.72" backspace, and that would work in the front too. So really, for the larger rims, the 65-67 B rear is ideal, because it matches the front and rear backspacing.
It would be even less of an issue if you had a Barracuda or Duster, I run a 68-70 B body rear in my Duster, which is a whole 1.5" wider per side, but it has a lot more room to the quarters than a Dart.
Since you're moving the perches anyway, grab a set of offset hangers/shackles from Dr. Diff. Moves the springs in a 1/2" so you can run more tire, should be able to get up to a 275 with that offset. :D