Spy Photos: 2013 Ford Mustang Shelby GT500 Coupe

Spy Photos: 2013 Ford Mustang ShelbyOnly a month after the unveiling of the 550-plus-hp 2012 Chevrolet Camaro ZL1, word is leaking out that Ford will substantially advance the muscle-car wars with a 2013 Shelby GT500 making a pants-bursting 600-plus horsepower.Our well-informed sources say the stratospheric output figure, which could be as high as 620 horses, is the result of boring out the