Vibration after BB, TC drop or shim or both??

Not sure what the stock height is, mine were beginning to sag. Ended up getting 20" from center. Could you tell me what the stock height is with good stock springs? I'll like to know how much I ended up getting.

After test driving it, I have some vibrations. Not sure if a transfer case drop alone would help or do I also need to add shims at the axle?

For you guys who have corrected this problem, what method did you use?

Thanks..

Was planning on going this route..
http://www.go.jeep-xj.info/HowtoTCdrop.htm

Jeepwire.Com Presents: Setting Your Pinion Angle 17 " & 17.5.. this will help.

do the drop, quick and easy

From reading different posts. Looks like there is one stud on each side that is a pain to remove. Guess I'll find out...