These BBK Performance shorty tuned Length exhaust Headers are designed and constructed as direct fit replacements for all 99-04 Ford 5.4L F150 truck applications. Each header is manufactured with 1-5/8" CNC mandrel bent tubing that offers unrestricted exhaust flow for increased horsepower and torque over factory OEM manifolds. BBK tuned Length headers offer improved scavenging waves for better combustion which leads to improved performance and fuel economy over stock or equal Length headers. As with all BBK Performance exhaust headers they feature a 3/8" laser cut flange for additional strength and a guaranteed leak free fit. All headers are robotically and precision hand welded and then pressure tested to ensure years of reliability and performance in the real world. All BBK exhaust headers are available in a bright chrome or polished silver ceramic coated finish and include new exhaust header gaskets header bolts and hardware to complete the installation. 50 State Legal - CARB APPROVED