Sky's the limit! I've seen 6" body lifts on top of 6" suspension lifts, but that's really dumb for several reasons. Read the sticky at the top of the 3rd gen page. Why do you want the biggest lift available? For function, you'd want the smallest lift you can go with the largest tires. A lot of Hawaiians go nuts with their lifts, they would tip over if you leaned on them too hard.