I've got the 3" (max) Ready lift kit on mine with 33x12.50 Tires. You can go up to 35's, but I don't have the cash for a different set of wheels to help keep a 35 from "bulging"
Really nice kit, seems super strong
You can see the pics of it in my photo albums on my profile
'04 F150 4x4 3" Ready Lift Leveling Kit, 33" Dick Cepek FC-II's, Airaid Cold Air, Airaid Poweraid TBS, Xcal3 Dyno Tuned, No Muffler-single outlet