Originally Posted by newmoon
620 was the highest I have seen, actually it was 619, there are however numerous cars that are pulling 600-610s rwhp. It really is amazing and I suspect Ford under-rated this car a bit. These cars are also trapping as high as 127 mph stock in cool weather, which backs up the dyno numbers. I think it's safe to assume that the 500 is producing every bit of it's advertised hp and then some.
I seriously doubt Ford would unrate the car over a 100 hp. This is the press release. If someone is get 620 rwhp, they are not stock, maybe its tuning (I doubt), but they are not stock.
*UPDATE: We've received an official press release from Ford quoting power figures of 662 horsepower and 631 pound-feet of torque, making the 2013 Ford Shelby GT500's engine the most powerful production V8 in the world.
Originally, Ford was rating it at 650 hp. If they updated and added 12 hp, they would not under rate it over 100 hp.