This alternator will fit any 05-08 Mustang GT. It is a bolt-on upgrade to the stock alternator, though you will want to increase the size of your alternator power cable to handle the increased juice. A great upgrade if you have aftermarket amps, lights, fans, etc. Put on my car in the fall of 2018 and only driven about 3k miles. Selling only because I'm converting to a DOB supercharger from my Kenne Bell, and I'd rather buy a new alternator from DOB than hack this one up to fit their system. Works great. Costs $350 plus tax new. Selling for $200.