I just got the new issue of the MMFF and they did a review of the new 2013 GT500 and it sounds sick. From what I can remember from the article it makes 650 HP 600 FT/LBS on 15 lbs. of boost. The displacement has been bumped from 331 to 355 and the blower has gone from the TVS 2.0 Liter to a TVS 2.3 Liter blower. The compression ratio went from 8.5-1 to 9.0-1 and the motor now has an 8 quart oil pan. They also moved away from the 2 piece steel driveshaft to a one piece carbon fiber unit that weighs 26 lbs. I guess the torque management system is supposed to be really aggressive and really geared for track use/getting out of the hole fast. Since the car is a torque monster the gearing dropped to a 3.31 from the 3.55's. At the track I think they were able to knock down 11.70's in stock form. They feel the car could greatly benefit from some 4.10's and a tire which would probably put it down in the low 11's or high 10's.