The regulator is built into the fuel pump sending unit which is in the tank. Like Smokin said, it is a dead head system and pressure cant be changed on the stock system. The factory rates pressure at 50 psi for idle and 55 psi for WOT on Gen 2's. Depending on what you are trying to do, there are ways to tweak the fuel system for more or less fuel volume and pressure. Unless you have a really good reason to do this, then I suggest you leave it alone.