I use a diablo tuner with my 2001 F350 7.3l. It rocks. Especially when you have her in +100 Hp.:d:d Quick and easy to use also. Plug it in and 5 minutes later you have your changes. Anything from towing, economy to + 100 Hp. Best money I spent for changes to the truck.
They run about $450 and don't install, just plug into your service port for your computer. You only plug them in to change the program to the new paramiters then unplug and play. You can also use it to do real time testing and charting. Monitors transmition,engine and most other stuff the computer watches.