friend of mine has an 03 7.3... he has:
4" turbo back into 7" stacks
home made intake (took it off a cat bulldozer i believe :D)
water- meth injection
5 different tunes (1 being mild, 5 being wild <--- trust me, its wild :D)
believe me, it is set you back in your seat and/ or roast the tires...