It is alot of money to make them go fast. You don't just have to buy a chip to get to 400... LOL
The 7.3 shown above has a GT42 turbo, Hybrid injectors, BTS transmission, Headstuds, Valvesprings, fass fuel system, water injection and a custom chip from BTS. The truck dyno'd at 490 horsepower.... not bad for a 7.3.