I have MORE boom shackles front and rear. They are VERY beefy and should only be about $100 / set. In the rear booms kick the shackle out so it does not bind on the frame and in the front in you invert them so they look like a 7 from the side, they prevent shackle inversion and save your leafs. Booms do not do anything to improve ride quality or anything. If you want to improve ride quality on a YJ you need good quality shocks and high-end springs like OME or Alcans.