Carroll Shelby’s idea was simple in the way that most transformative ideas are simple: take a light British sports car body, remove its inadequate engine, and install an American V8 of sufficient dimensions to make the result deeply alarming. The AC Ace weighed approximately 2,100 pounds. The Ford 427 cubic inch side-oiler V8 produced around 485 horsepower. The arithmetic of this combination — a power-to-weight ratio that embarrassed Ferrari and Corvette simultaneously — produced a car that was genuinely dangerous to drive and genuinely faster than almost anything else on a straight road in 1965.