Hi there,
A few things come into play... first if yours is a 2 door and his is a 4 door, he is heavier. I am a firm believer of proper break-in periods. A good friend of mine and I got our GTP's that are IDENTICAL with buid dates a touch over 1 month apart. His was beaten on right out of the parking lot, mine was babied for the first 2500 miles. I take him EVERY time in the 1/4 mile by about 3-4 car lengths. Driver technique... a little spin compared to a good launch can cause a big differnce in outcome, even to 60mph.
I think its more a combination of the above points rather than your having some freak car. Now if you told us that you can do consistant 13.5's @ 103mph with your car's current mods, THEN it would be a freak.