You should hit a high 12 pretty easily (under 2.0 60'). I know a guy who has a 99 GT auto. He has exhaust, 3.73's, and a P1 putting out 10 psi. He ran a 12.72 with his stock tires
Trapped 111 if I remember correctly. He might have gone faster but they kicked him out because he didn't even have a helmet. Oops.