The Powerbox is a direct replacement upper intake that bolts onto the stock 5.0L Mustang lower intake to produce a 20 horsepower increase at 4700 RPM on a stock engine! That means a broad power band that keeps pulling to the 6250 RPM rev limiter plus improves 1/4 mile E.T. by.3 seconds. And, according to dyno tests, Powerbox meets or exceeds the breathing ability of Ford's GT-40 intake at all points of the horsepower curve! Gain an additional 300 RPM's while dropping 16 pounds of engine weight. Constructed of indestructible, heat resistant composite material. Complete with all gaskets, vacuum fittings, bolts, hex key wrench, silicone sealant, instructions and instruction video.