jayfotos, your shop guy is clueless. List of reasons why:

1. The Fuel Pressure Regulator offers a range of pressures depending upon vaccum. (Vacuum= low fuel pressure; no vaccuum is high fuel pressure). The new fuel pressure regulator simply allows the high mark to be a bit higher. It's never higher than the fuel pressure generated by the pump.

2. Fuel volume (into the engine) is controlled by a combination of fuel pressure and injector duration. All factors being equal (no supercharger added, O2 sensor reporting "just right" mixture) increasing the fuel pressure will cause the computer to decrease injector duration to compensate. Unless of course, you add more air. ;-) By blowing it in with a fan. Which you are doing with supercharger. So, the engine computer will always try to achieve an ideal mixture under all conditions, including if you force air into the engine. If you do, it is likely that under top (factory regulator) fuel pressure and full S/C boost that the injector duration will reach its programmed longest length of time and still fail to get enough fuel into the intake. This will result in a lean condition. To compensate, simply install the fuel pressure regulator that came with your s/c kit to allow the computer to shorten duration and still add enough fuel to allow for ideal mixture. (Not too lean). If you leave the stock FPR in place, you WILL run lean and MAY blow up the engine. You will probably throw a code first, though. (Lean condition). The regulator in the kit is specifically chosen for your engine under boost. It's critical.

3. Rich conditions don't blow up engines. They sputter, and spew out black smoke, but they don't damage the engine. (Catalytic converter is another story).

Nate