Stock gearbox on 88-98 sucks. Every 4wd lifted or not and even my 2wds get slack in them beyond any adjustment. I used a 02 2500 box on my 96 and it was a big improvement. Everything is direct bolt in EXCEPT steering shaft. I'm a machinist for the most part so I cut rag joint end off, cut the 02 u joint end off, machined a solid shaft piece 1.5" that pressed into both parts and welded it. I'm sure there is a rag joint with correct end out there but I don't like rag joints anyway
Got any pics?