Installing a set of Ford Truck underdrive pulleys gets back HP you lose to your accessories. And by purchasing a quality Ford Truck underdrive pulley from a brand like BBK, you'll also enjoy all of your truck's full original cooling and charging characteristics. Upgrade your Ford Truck's throttle body or intake at the same time to get the kind of power that'll leave you with a white knuckle grip on the wheel, and will leave other racers with white faces.