You may or may not need the sye/cv. But you'll definitely need one if you do a TT in the future. Just put the lift on and wait for it to settle for a few days. If you still have the vibes, put the tcase drop in and start looking at an sye/cv.
1998 TJ, 2.5" OME springs, OME N66 & N67 Sport Nitro Shocks, 33x12.5 Goodyear MTR's, Metalcloak front trackbar, JKS rear trackbar, Metalcloak aluminum front arched fenders, Metalcloak aluminum front bumper, thedirtworx tire carrier, Warn xd9000i w/ synthetic line and TRE Safety Thimble II, Monstalined interior