It's not even the IFS so much as it is the fact that they have you drill a BIG @$$ HOLE in your cast aluminum steering knuckles. Of course they fail to mention this fact before you buy their kit, but hey, that doesn't really matter does it? (note the sarcasm please) JeepinAl (another member of the L.O.S.T. boards) pioneered his own 5.5" lift kit using factory knuckles, custom upper arms, an SYE new rear control arms, etc. but the stock diff. and CV's, but he did have to drop the diff. cradle slightly and i believe the T-case and possibly transmission as well. But i'm not sure. It can be done, but RK just does it the wrong way. As '03KJ said, it's a nice lift, until you use it...