were you guys successful in getting the diff brackets complete??
Yes, mine was sitting at 4 1/2" at Moab last year, but I was tearing boots. Mine have been done for quite some time now. The diff drop lets you lessen the angle of the CVs by lowering the axle center section where the inner CV cups mount up. By dropping it down, you have less stress on your CVs. Most people use this to bring their ~3" lifted CV angles down closer to paralell with the ground. When you lift 3", the outer CV drops down 3", while the inner stays the same. What the drop does is move the inner CV down 1.5" to 2" depending on how far down you made your brackets go. This makes a 3" lift look like a 1.5" or 1" lift to your CVs. What I did on mine was use the 2" the drop gave me to move my outers down even more. You should also be using low profile or ultra low profile bumpstops on your upper A arms or you won't be able to crank the torsion bars enough before they hit the factory bump stops. Another thing I had to do was re-index my torsion bars which means unloading them, pulling the mounting brackets off, letting the A arms fall to approximately lifted angles, then reattaching the torsion bar brackets and reinserting the rods, and then cranking them to normal specs. If you don't do this step, you are placing excessive stress on the torsion bars which makes them either fatigue really fast and lose springiness, or simply snap. That's why no one likes lifting above 3". Above that, you have to do a lot more work. I had to replace my rear factory bumpstops in the back with larger aftermarket versions and 2.5" square steel spacers to make the rear axle articulate properly, plus use coil spring compressers to even get my spacers in place. I could probably also use longer shocks in the rear, but I haven't had any issues with that yet, so I'll wait till I do. I also ran longer brake lines all around so I didn't run the danger of snapping them off when stuff begins to move.