I know there are numerous way that you can tune your vehicle, but I'm not really sure which one is best for me. I have a 2004 silverado rcsb with a 5.3; currently only I have a cat-back exhuast right now, but I am about to upgrade quite a few things. Within the next couple of weeks, I will be adding longtube headers, removing the cats, either true duals or flowmasters muscle truck system, k and n intake, and electric fans. My truck was originally not equiped with electric fans, but I want to controll them from the computer. I want a tune that is open for changes, because I if I do a cam swap, I want it to be as simple as possible. However, if I do not swap the cam out, then I will be swapping the motor out for an LS6, LQ9 with LS6 heads and cam, or some kind of build motor from an LSX block. I recieved advice that recommended a diablo sport predator U7193 for now, since I can do a performance tune, delete the rear O2, controlled electric fans, and adjust speedometer and tire size; and when I'm ready to do major engine mods I can go to a CRM dealer and have custom dyno tune put on my predator. I have also heard many good things about Nelson Performance and what great customer service they have. The option of buying HP Tuners has crossed my mind to since I like the idea of tuning my truck myself. Alright well I've told you about my truck, now I just need some advice. Thanks