SuperMAXX Stainless Long Tube Headers are an excellent way to bolt on 20 hp and 14 Ft. Lbs. of Tq. to your 1999 2003 Ford F150, 1999-2004 Lightning or 2002-2003 Harley Supercharged Truck with a 5.4L engine. Although a tune is recommended, these power gains were before the tune! A power tune could add another 20-25 hp. 100% Stainless Steel construction with a Limited Lifetime Warranty makes the SuperMAXX header second to none. 1.625 primary tubes and a 2.50 collector make a great combination for stock engines and/or upgraded power plants. Fits with automatic or manual transmissions and takes about 4-6 hours to install. Comes complete with a detailed, full color instruction manual for easy installation. O2 Extension cables, triple layer stainless steel gaskets, header bolts and all installation hardware are included. Designed for use with Dynatech intermediate sections (part numbers 722-84220 or 722-84320).