I have located a "brand new", in the box, TRD supercharger for my 2003 Tundra 4X4 Limited 4.7 (V8). I can get it installed by A Toyota Dealer for a total of $3,820.00. Is that a fair deal? Do they really make a huge difference compared to the personal upgrades I have done? I would put my Factory Air Intake box back on and omit the Throttle body spacer. I would keep the exhaust I have put together. Do you also need to run different plugs? Last of all, are they reliable? Thanks for any input on this.