71 duster 7 1/4 - 8 3/4 conversion

Are the u bolts same size ? Where and what to order to bolt this thing in place.

also I have the larger break option on it with large bolt pattern axles . Because it came that way . Can I get small bolt pattern if I wanted to put on ? Or will that not work?

Stock it’s. 71 duster 198 slant 7.25 rear with 7.73 gears I think

I have a 4 speed 833 set up to bolt right to my slant , and new 8.75 rear with 3.23 limited slip rear to put in this car over winter. Trying to have all parts ready to rock for this conversion