the dreaded Death Wobble!
Ironically though, when my boyfriend is in Jeep with me, it doesnt do it as bad??

No! not unless the lift is the direct cause of your problems
I was having the death wobble problem at least every 2 to 3 days. Mine ended up being my Heims joint. (Normal wear and tear) 20$ part threw it on took it in for a new alignment and I have not had it since.
RC recommends 130 lbs
http://project-jk.com/wp-gallery2.php?g2_itemId=49335


