a lot. first you need an axle from about 77-79 light duty f250. then you need to clean it all up (grind off existing spring perches), measure to make sure she sits even under the truck, weld on new spring perches, etc....lots of work. i am going to be working on this project hopefully starting this time next year when i move back home to Iowa and have my garage. If you are not very mechanically inclined and good with welding, gonna cost you a pretty penny to get this done. then you have to run wheel adapters in the rear cuz you wont have 5x135 up front anymore...