Help with my lowrer u bolt bracket for an 8 3/4

[64whiteghost]

Whats up guys.

So today i tried installing my new 8 3/4 that was shortened to A body spec. I thought i could use the same u bolt bracket ( not sure if thats what it is called. But I posted pictures) so the u bolts I got from espp springs are wider and bigger. Do i need new brackets ?

 

[Dana67Dart]

Yep you have 7 1/4 "shock plates"

The u bolts are smaller.

Also if those u bolts are not flattened at the top of the U. You WILL crush the axle tube.

I bought a housing and you could see where the round u bolts were installed and over tightened on the outside AND on the inside.

On the outside a perfect 1/4 round impression into the powder coat.


The torque spec is 45 not 100 lbft.

 

[Professor Fate]

I thought i could use the same u bolt bracket ( not sure if thats what it is called. But I posted pictures) so the u bolts I got from espp springs are wider and bigger. Do i need new brackets ?

Technically, yes. The shock plates are different between the 7 1/4 and 8 3/4 rears- since the 8 3/4 has larger axle tubes, it requires larger U-bolts, which in turn means the shock plates have different hole spacings.
You have two choices:
Get the correct shock plates (8 1/4, 8 3/4, and Dana have the right spacing) used, or new from various vendors such as Doctor Diff, Mancini, ARE, or Summit.
Mopar Shock Plates
Shock plate, stock style | AR Engineering
Your second choice is to oblong the holes in your existing plates so the bigger U bolts will fit- this may also require some judicious grinding to the plate edges for the nuts to seat and so you can get a socket on the U bolt nuts. Kinda hillbilly, but it works.

 

[69FBCuda]

Copied from: 8 and 3/4 yoke change
@Oldmanmopar