After I got done my lift I drove it for a day with stock tires, but not over 45-50mph. Now with alignment and 31" mudders it is really noisy(like mudders). The rear tires are cupped pretty bad and make a lot more noise from 50-60mph. I'm pretty sure it is just the tires, but if I had a driveline vibration, at what speeds would it vibrate? I am going to do the trans case drop if neccesary, but I am pretty sure the bolts are going to snap. My rear lift is stock springs with a 2" block and 2" shackles.

99 Sportage 2Dr, 1.5" body lift, 30x9.50 Cooper M/T's, high lift, CB, custom bumpers, Warn manual hubs, Tom Tom GPS, snorkel.
99 Jeep Cherokee 3" lift, 31" mud terrains