The Shelby Drop is the rare classic Mustang upgrade that costs nothing but a drill bit, an afternoon, and a willingness to put a permanent hole in an original shock tower. It relocates the front upper control arm about an inch lower, rewriting the camber curve and cutting body roll on a chassis Ford tuned for boulevard comfort. Shelby American did it to every GT350 and GT500 of the era, and Ford’s own assembly line never followed. Read on for what it actually changes, and what it cannot.