These headers are designed to improve your vehicle's exhaust flow, resulting in increased horsepower and torque. Inlet / Outlet: 1.875" (8x Manifold Ports) / 2.5" (Outer Diameter).
Main Pipe Diameter: 2.5. Standard Graphite Manifold Gaskets and Mounting Hardware Included. 2001-04 GMC Yukon (except 2003 GMC Yukon SLT Sport Utility 4-Door 5.3L). 2000-04 GMC Yukon XL 1500.