A one-inch adjustment to the front suspension, developed quietly by Ford engineer Klaus Arning for Carroll Shelby’s GT350 and GT500 builds, remains one of the cheapest real handling upgrades in the classic Mustang world. No new parts are needed — just a drill and a willingness to relocate the upper control arm mounting point. The payoff is a measurable drop in body roll and a reshaped camber curve that keeps more tire on the road through a corner. Here’s how the Shelby Drop actually works and why it still matters.