When the Roush 380R arrived in 2003, based on a standard Mustang GT, the Stage 3 offered an Eaton Roots-type supercharger with an air-to-water intercooler, a new intake, a secondary sheave front ...

Roush offers supercharger kit for Mustang GT, boosting power to 810 hp ... looks and lets Roush re-use the stock air induction parts. That's a boon for engineering and for reliability.