[nu2-72]

I checked with the local parts stores and they tell me that 3/4 rotors are the same 71 up and the 1/2 ton and 3/4 calipers are the same.
Since the bolt pattern appears to be the same for both axles I would say they are the same for mounting brackets. The only difference that I have discussed with people that make the flat brackets is the spacers.
Since I have made my own spacers, I do not need theirs. Many of the spacers provided are pipe cut to length. I have machined solid rings to provide 360 degree support.
Also, since you are going to 4 wheel disc and using front rotors and calipers you can modify the backing plates from a 4 wheel drive.
Thats how they hold them on the front. Difference is the front mount is 6 bolts and the rear is 4. Also the ID of the rear is slightly larger than the front and has to be opened up.