Flowmaster 814123 Header 409S - Block Hugger - 2.50 in. Stock Flange Outlet - Pair

On a 2004 Silverado 5.3L, power gains of 14.4 HP and 22.5 LB. FT. TQ 3/8in. Thick Laser Cut Flanges Dyno tuned for maximum performance High Temperature Ceramic Coating Stainless Steel Construction