You can't do a body lift on a unibody vehicle. How high you go on the lift to clear the 33" tires depends on what you plan to do with it. 4" is fine if you're just driving around town. 6.5" if you're doing some serious offroading. You'll probably need wheel spacers or aftermarket wheels to clear the shocks in the rear and the lower link in the front.
A forum community dedicated to Jeep Grand Cherokee owners and enthusiasts. Come join the North American Grand Cherokee Association and participate in discussions about performance, modifications, classifieds, off roading, trail reports, troubleshooting, maintenance, and more!