OK I got the leveling kit installed because I had some issues with the front tires rubbing. But now the rear end looks to be sagging. I got some 2" blocks but the guy I got the blocks from does not have the U-bolts. I need to know what size u-bolts I need. And also the blocks I have only have one pin. Do I need the three pin blocks or not. Is the axel a 3" or 3 1/2".

 

First off, you should probably get the CORRECT 3rd-gen blocks with the triple pins.
Second, if you only want 1 1/2" in the rear you can remove one or both of the 3/8" plates.
Third, your axle tubes should be 4" diameter (actually I think they are 4 1/8"?)