in the process of fabing my own lift, 3 inches shackles/blocks stiffer springs, but what would be a good angle to cut the blocks at i was going to cut 10 degrees, but would that be to much or to little for the wheel base (77 cherokee), and dont worry i work at a fab shop and im in tech for welding, this is also where i cut off the fender flares , and channel to replace the rockers,

cut fenders,3 inches of lift, to much for 35s? 

Fab up some temporary blocks out of scrap tubing. Install the rear axel and use an angle finder to determin the corect angel for the rer diff. Then cut your blocks to the corect degree.  

thats a good idea, but on the ther hand we have lots of scrap, and a band saw,i think ill try that with an i beam though