Use floor jacks to raise the sway bar arms into position. Place the jacks in front of the installation plates rather than the rear to keep the sway bar from rotating upward behind the differential. Raise both arms evenly to firmly place and test-fit the chassis mounts against the bottom of the framerails. The final position of the two mounts is with each one completely touching the bottom of the rear subframe and inside the upper part of the bracket touching the horizontal portion of the upper control-arm mount. Use enough force with the jacks to hold the chassis mounts firmly against the bottom of the rear subframes and tighten the four axle-mount U-bolts. The U-bolts need to be tightened to hold the sway bar assembly in place for welding (or drilling for the bolt-in version). Tighten both ends of the U-bolts evenly.