Silverado & Sierra 1 3/4" Longtube Headers & Y-Pipe 2007-2013 (4.8L, 5.3L, 6.0L) 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) Will work on 6 Speed Transmissions Gains over 25rwhp