I put in a RE 2.5" STD lift with Currie Boomerang and tow shackles a few months ago on my 95 YJ 2.5l AX-5 Jeep. I used the shims and the transfer-case drop supplied in the kit. I have a pretty strong vibration when I de-accelerate in gear. It seems to roll pretty smooth under power but I do feel some vibration at around 65mph. Is this normal?
No. I would check the rear pinion angle. One problem with using shackles that give you any sort of lift, like the Boomerangs, is that they also change the pinion angle ever so slightly. Make sure you're shims are in correctly also. Big side facing the front of the jeep. Having it the other way will cause the pinion to be pointed the wrong way.
Also, I'm assuming you don't have a locker or LSD of any kind in the front as this can cause vibrations in the drive line since the front driveshaft isn't balanced very well, stock.
