BFord Mustang 2x3-1 Design Stainless Steel Exhaust Header Kit (Polished Chrome) 4.0L V6 ReviewbP PP Ford Mustang 2x3-1 Design Stainless Steel Exhaust Header Kit (Polished Chrome) 4.0L V6 PMade of high quality steel with 2-pieces 3-1 direct bolt-on designPTIG welded CNC machine flangePEGR bung insertion Metal gasket included Inlet: 1.5" Outlet: 2"PIncrease high flow air, instantly gain 10 to 15 Hp.