I too am traveling down this same road. Although I wish to keep my power down a little more and have complete driveability and total assurance that my truck wil keep running every day with no breakage. If you eally are looking for that 450-500 hp number you will need a billet transmission, at least input shaft and probably intermediate as well. A valve body, billet torque converter and a few other mods in the transmission. The output shaft can be replaced when you break it without pulling the trans. A stock exhaust even being straight piped will not let the air run free enough to get you where you want to be hp wise. You will need a larger exhaust and larger intake (AFE or equivalent). Your stock turbo is too small to push anything other than stock injectors and give you any advantage other than smoke (unburned fuel). Garret makes some really nice turbos and you can also go with a hybrid. But the diameter of you turbo is only 9cm, which will only allow x amount of air through it. You can tweak your waste gate and j bolt it for more boost. Keep in mind when ou increase boost, the turbo will run mush faster and wear out sooner. How about your lift pump and injector pump. When running a box that has been tapped into the injection pump, you wil need more fuel on the higher settings.