Maximizer Long Tube Header For 14+ Chevy Silverado 1500/ GMC Sierra 1500 5.3L

Improves performance, efficiency, and horsepower ~12-16 Horsepower Gain Mandrel bent for smoother exhaust flow Dual T.I.G. welded construction for stronger hold  No installation instruction included in this kit, we recommend professional installation Manufacturer's Limited Lifetime warranty against manufacturer defects (Must fill out and return warranty card with a copy of the receipt and within 30 days of purchase date) Primaries: 1.75" OD, Port Shape: Oval, Port ID: 1.5" ID x 1.8" ID, Collector: 2.5" OD, Outlet: 2.9" OD, Main Piping Size: 3" OD, O2 Bung: 4, EGR: No