5.4L V-8 engine only Banks' 100% stainless TorqueTubes are virtually indestructible. Includes two full exhaust manifold assemblies, each with a seamless high-velocity collector. Unlike the restrictive stock setup, Banks TorqueTubes literally "pull" out the exhaust, unleashing greater torque and helping the intake stroke to draw in more air. (V-8 only) Torque Tube Exhaust Header System for use with 2004-2008 Ford 5.4L F-150 and Lincoln Mark LT V8 Virtually indestructible 100 percent Stainless Steel Mandrel-formed tubes tune exhaust flow for maximum torque Maximizes exhaust extraction Flanges welded on both sides, then milled flat Seamless high-velocity collector Pulls exhaust and slashes backpressure Includes two full exhaust manifold assemblies 5/8 inch thick flanges won't warp or flex Includes all necessary hardware Emissions Compliant: D-161-105 US Patent #6,634,171 B1