The epic battle between Ford and Ferrari reached a flashpoint in 1966, when Ford GT40s swept the podium at Le Mans. Clearly, the 330 P3 needed a revision to compete the following season, and engineers swarmed over the car. The resulting P4 looked identical from a few steps back—onlookers were surely confused when the first P4 first saw light of day, wearing nearly the same beautifully sinister lines. However, a closer look reveals significant changes that perhaps only became obvious when P4s swept the podium at Daytona as payback for the Le Mans humiliation the year before (and providing the new Ferrari 365 GTB/4 its famous nickname in the process). Of the changes, the most important from a competition perspective was an extensive reengineering of the 330’s powerplant, the largest Lampredi V12 in Ferrari’s arsenal. Fitted with a new three-valve head and fuel injection, it is good for 450 horsepower. The slightly shorter P4 only weighed a ton, so performance was (and still is) staggering—more than enough for Ferrari to capture the Prototype Championship, and also more than enough for the FIA to jump in and limit next year’s prototypes to only three liters, effectively ending the careers of both the P4 and the GT40.