DNA Motoring HDSTT0134L Stainless Steel Exhaust Header Manifold Made of high quality steel with 2 x 3-1 direct bolt-on design TIG welded CNC machine flange O2 sensor bung insertion / Metal gasket included / Inlet: 1.375" / Outlet: 2.5" / Y-pipe: 2.5" 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)