Asking a Mega Cab to be fast is like asking a Toyota Pryrus to haul a 30 foot 5th wheel camper. However, that being said, there are some pretty impressive Mega Cab's out there. If you look at Carli Suspension's web site, they have a white one that is amazing (I think the web site is thecarlisuspension.com or something close to that). Also, Kore (koreperformance.com I think) has a pretty good setup for one. Neither setup is going to make them faster, but they will make them handle a lot better than the stock setup.