I wouldn't modify the engine. Take out some weight, some suspension mods, and the car would be better than it already is.
The Bullitt is my favorite Mustang. It has a nice purposeful classiness to it. The Shelby is next. The others seem too aftermarket to me.
By the way, has anyone seen what the Mustangs are doing in the Continental Tire race series? BMW and Porsche has...from the rear.
