Join Date: Dec 2005
Location: West Bountiful, UT
I've been running the factory shaft on my LJ with 3" lift and Medic TT for 125K without vibration. Except when the u-joints were letting me know they were tired.
There is a MML installed too, which definitely helps with the angles.
If I'm remembering right (never a sure thing...), I had to adjust my pinion angle down slightly (not up, as you would with a CV) to match the t-case.
Anyway... CV might be your solution. But you can definitely make the factory non-CV live a long happy life on the LJ with your lift height.
'06 Silver Rubi Unlimited, 6 spd, Currie arms, Nth springs, AEV Highline, 35" KM2's.