that is called an internal wastegate. Some turbos have them usually smaller up ones. Others have external wastegstes usually on larger turbos. What you need to find put first is if anyone makes manifold for your car otherwise you hot lots of fab work ahead1. Expect a twin system to run 6000 to 8000 in parts alone. Two of everything. Engine management injectors etc . If there is a bolt on super charger the yu might be better off with it . Don't let the mustang make you dislike superchargers. Sorry for the spelling on I phone