For Chrysler Small Block 2x4-1 Design Stainless Steel Exhaust Header Kit (Polished Chrome) V8 Made of high quality steel with 2 x 4-1 direct bolt-on design TIG welded CNC machine flange Metal gasket and reducer included / Inlet: 1.25"x1.7" (Oval) / Outlet: 2.25" 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)