Riddle me this.... Vibration riddle

SOOOOOO ever since my lift ive had vibes (97 sport 4.0 5sp rough country 4.5" lift) simple fix right? just put in a sye new dshaft and run with it. Well I couldn't afford all that jazz and put new u joints all around. well today i blew the ujoints in the front shaft. so i unbolted it... My jeep has no vibes at all now. Kind of odd imo.

Pardon my lack of knowledge on the rough country kit, are the arms adjustable? if so is the front d-shaft at a happy angle?

Your caster is off putting your front shaft in a bad angle causing vibes?

The RC lift i got is full leaf packs fixed short arm. I am ordering adjustables soon. And yes I am thinking my caster may be off throwing the shaft out of lines and causing my slight deathwobble.

How is the slip joint on the front shaft? Does it have any radial play in the joint? It isn't uncommon for the front slip joint to go south, and cause drive line vibrations. Even though it isn't under power in 2wd, it is still turning the same speed as the rear shaft, and therefore just as likely for any vibrations that may occur.