You can run 35's with just a leveling kit. Also I would not buy a leveling kit. I would just get some longer shocks instead. You can get just as much lift with the stock keyways and you can with aftermarket ones. If your not going with the rancho I would just get these-
http://cognitomotorsports.com/store/Hummer_H3.html Or if you have a lot of money to spend get these-
http://www.samcofabrication.com/prod...products_id=48