One other key big difference would be that the Stage one kit includes a single 92mm GT500 throttle entire body, while the Stage two package comes along with the billet 112mm round throttle system (which uses GT500 electronics) that we talked about before. Word on the street is always that https://ford-mustang-gt-whipple-s58025.sharebyblog.com/24745760/2007-ford-mustang-gt-whipple-supercharger-no-further-a-mystery