2003-06 Chevy/GMC 6.0L (4WD only) Truck. CNC Mandrel Bent 304 stainless steel construction, 1-3/4" primaries, 3/8" thick CNC Laser cut flanges, 2 1/2" catted leads. Designed to connect to factory exhaust. Stainless Works headers are backed by a limited lifetime guarantee on material and workmanship and are made in the USA.