1999-02 Chevy, GMC 4.8L, 5.3L (2WD only) Truck headers. Made from 304 stainless steel, for maximum corrosion resistance. All tubes are CNC mandrel bent for optimal flow. 3/8" CNC laser cut flanges. These headers come with air tube fitting on primary and 1-3/4" primaries that flow into a 2-1/2" slip-..