rear spring u-bolts
Mancini racing has many
The u bolts have a flat on the U end of the bolt, and the nuts are self locking.
The torque spec will be in the Factory Service Manual. IIRC it is like 45 lbs.
Too much and/or the wrong U bolts WILL crush the axle tube.
I am assuming 8 3/4"
Dana 60 and 7 1/4 are different tech