U Bolts from a Dakota rear end working on an 8 3/4. Has anyone used this or heard of this.

pressure applied to the tube under the U bolt U = Force/Area

spread the force over a wider area = less pressure

i.e a perfectly round U clamp tends towards an infinitely small contact patch on the axle tube massive pressure over a small area causing damage to the tube

fat flat U bolt spreads the force over a wider area for the same torque on the nut

contact patch has an impact on friction between the two clamped items
bigger patch results in more friction up to a point.

not really about Tubes rotating at all. if it gets to that point all is lost.

U bolts need to provide enough friction between perches and the saddle on the spring so that the rivet or bolt that holds the spring together is not put into shear stress by the action of the perch-hole against its head when car is under acceleration.

i presume the torque specified for the mopar set up and a round U bolt resulted in kinked axle tubes and it didn't for the flattened u bolts

they won't have F++ked about doing an extra process that costs money when making the U bolt if it wasn't considered necessary for the intended use

but i do note that mostly nobody else did this....

Chrysler obviously had their "Extra care in engineering" reasons to spend that cash.

or maybe they just had a really **** bending machine :)

Dave