I installed a rustys full pack 3" on my 98 about 3 weeks ago. I had to pull the bottom leaf to get the rear down to 4". My rear pinion was close to the t-case angle after a .75" drop. I used aluminum square stock, and Im going to try 1" stock to drop it alittle more. Right now it has some vibes, but not bad. Between the extra drop and the springs breaking in some, I should be vibe free. The u-joints are close to their max working angle so I will eventually go sye to properly FIX the issue.
My front end has no issues. I will be putting a 1"spacer up there to level it, but dont predict any problems.