The Edelbrock supercharger Stage 1 Street system part #1581 for 2004-08 2-Wheel Drive Ford F-150 Trucks increases the performance of your 5.4L 3V engine to 478 horsepower and 504 ft-lbs of torque at the crank. The core of this system is the Eaton Gen VI 2300 TVS rotating assembly with a four-lobe design with 160 degrees of twist for maximum flow, minimum temperature rise and quiet operation for excellent drivability. We also designed our superchargers with an integrated bypass valve to help eliminate parasitic loss under light throttle, improving mileage potential. Our unique and efficient inlet configuration results in a shorter, less restrictive intake path for improved airflow, without the need for a jack-shaft. Keeping the air cool is a high-capacity air-to-water intercooler and low-temp heat exchanger. The Edelbrock #1581 system is 50-state emissions legal. The supplied tune is intended for completely stock vehicles with the exception of a cat-back exhaust.