There's literally nothing you can do to it to gain power, aside from injectors and turbos. The factory has certain criteria to allow certain hp ratings, which include radiator, intercooler, turbo, and a few other little things like EMISSIONS. There's only a couple aftermarket places that sell a performance module, and those dont really add that much.
Put it to you this way; I got a 94 with a 230hp DT466(with a few fueling mods), and an 06 with a 300hp DT466E. They will run head to head up to 40mph, and the older one will pass the newer one on hills. In a nutshell, if you want real performance, stick with mechanical injection. Unless you're willing to experiment with DIY or Extrude honed injectors, and different turbos.
