B body axle in A body?

[Gryzynx]

Ok, it's time to lose the 7 1/4 under my Cuda. Also changing to bbp disk brakes and V8 K-member from a 74 Dart. I may use the Dart rear diff for now just to match the bolt patterns, but it's another 7 1/4.

I'm aware of the option of the B body 8 3/4. I've even read that it fills the wheelwells better than the A body 8 3/4. I know it's about 4" wider, so my question is what would the recommended wheel offset be?

 

[dusted72]

If I remember correctly the B-Body rear will only fit in the Dusters and Demon/Dart Sports since they are wider in the rear area. They won't fit in a Swinger or Barracuda cause they are too narrow between the quarters.

 

[74scamp360]

i was always led to believe that you would have to shorten a b-body rear axle to fit any a-body. maybe i'm wrong???

 

[crackedback]

B body rears fit in A bodies fine provided you get the correct offset wheels.

A 68-70 B rear (60 1/8") is 3" wider in total than an A body 8.75 (57 1/8"). A 66-67 B rear is slightly more narrow than a 68-70.
71+ B rears are even wider than the 68-70

Perches are at 44" vs 43" for the A body. I've put them in before stretching the springs 1/2" each side. It's better to cut the perches off and place them properly.

They fit in ALL A bodies, get the wheel offset correct and you're good to go.

 

['74 Sport]

Aaron and I recently installed a '68 Charger 8-3/4" rearend into his '74 Duster.
We cut nothing and narrowed nothing, and you can see that it fits nicely. As Rob stated, the shackles hang at a slight angle because of the extra 1" width between the spring perches. But, we didn't feel like it was enough to worry about and move the perches the extra 1/2" on each side.

Since Aaron is off to college, we are in a slight holding pattern on choosing wheels; however, we did move his American Racing Torque Thrust II wheels over from his Dart Sport to take measurements. I will be calculating the backspacing we need for new wheels and post it as soon as I can.

In the meanwhile, here are a few pictures of the Duster with the 8-3/4". You can see there is plenty of room in the wheel wells, and there is clearance from the leaf springs. Admittedly, this is with 215/75-R14 tires and the stock steel rims and leaf springs from the Duster. Bottom line is... it works.

Jerry

 

[dusted72]

I appologize I thought they would only work in the Duster/Demon/Dart Sports my bad.

 

[Gryzynx]

Thanks for all the quick replies and especially the pics, Thanks '74 Sport.

I had a fast look under my absolutely stock setup, P205/70 14 tires right down to factory hubcaps and I think my results would look exactly like your pics. I measure 1 1/2" clearance to the springs and 2 1/2" to the wheelwell lip. Stands to reason that an extra inch of width on the axle would center the tires with the existing wheel offset. With the extra 3 inches of the B body axle, I would just touch the wheel opening lip, but I can move the wheels back inside the wheelwells with an inch of wheel offset adjustment each side. Of course, total width will still be limited to about 10" unless I move the springs inboard.