Chevy Silverado GMC Sierra Shorty Headers Truck 1999-06 (4.8L, 5.3L Engines) Mandrel Bent Tubing, CNC Machined Flanges Race Version with "NO" AIR/EGR Fittings, 304 Polished Stainless Steel 1 5/8" Primaries/2 1/2" Collector, Standard Graphite Manifold Gaskets 1999-2006 (2wd & 4wd) Gains over 15rwhp