Flowmaster introduces their manifold downpipes for 1967 to 1972 g C10/C15 1/2 ton 2WD pickups with small block V8 engines. These 2.50 in. mandrel bent 409S Stainless Steel downpipes fit only the factory angled ram-horn manifolds and include 3 bolt flanges, donut gaskets and donut sleeves. These downpipes are manufactured in the USA. These pipes can be used with systems part number 17654 and part number 817654 for a complete engine back installation.