I plan on buying a 04-07, 5.9, manual, 4x4. I plan on buying stock and giving it 400-500 HP while still being able to get good mpg's when I don't want the power. I have done research and I plan on building the truck so it can handle 600+ HP (at least 100 more HP then I want the truck to have) , my plans are to get a smarty sr with gauges or a smarty touch. straight pipe it with 4" or 5", 50-60 HP injectors, lift pump, ARP head studs, AFE or AEM intake and south bend NV5600 clutch. so what part of this do I need to change, not do and what do I need to do that I don't know about? thank you