'65 Mustang Hi-po vs '65 Formula S

Well, the Formula S was an actual production car, built on factory assembly lines. Shelby GT350s started out as production Mustangs, but they were sent to California to be converted by Shelby in his small race car shop by a handful of employees who revised their front suspension arms for better geometry, added Koni shocks, traction bars, wider wheels and tires and Galaxy rear axles with Detroit Locker limited slip. None of this was available on a production Mustang.