For Ford Mustang 2x3-1 Design Stainless Steel Exhaust Header Kit (Polished Chrome) 4.0L V6 Made of high quality steel with 2-pieces 3-1 direct bolt-on design TIG welded CNC machine flange EGR bung insertion / Metal gasket included / Inlet: 1.5" / Outlet: 2" Increase high flow air, instantly gain 10 to 15 Hp. / Tq Application: Please check part finder on top of the page (Professional Installer is Highly Recommended) (No Instruction Included)