Silverado & Sierra 1 3/4" Longtube Headers 2007-13 (4.8L, 5.3L, 6.0L Engines) Mandrel Bent Tubing, CNC Machined Flanges Race Version, 304 Polished Stainless Steel 1 3/4" Primaries/3" Collector, Standard Graphite Manifold Gaskets 2007-2013 (2wd & 4wd) Gains over 25rwhp