Efi Live is the sweetest tuning software for these gm trucks (diesel included). Check out some of the guys using it on performancetrucks.net and you will instantly become addicted. This software opens up another world for tuning, you can get your truck dialed perfectly and datalog for various tunes (mileage, power, anti-lag, etc). My tuner uses efi live with wonderful success, the programming is pretty easy once you get used to it but is kind of intimidating if you don't have any programming background. Try looking around the efi live forums and see if it's for you or if you just want a really good tune and call it a day (I'm lazy and the nearest awd dyno is 40 miles away).
