The Oval Velocity Stack is machined out of solid 6061 aircraft quality aluminum. This velocity stack is designed to be used in conjunction with our new Oval Runner Extrusion and any of our intake plenum materials. Perfect for all of those builds that have oval ports on the head. Where you may have once been stuck converting to a round runner shape, now you can maintain a solid shape throughout. Even though the stack is oval, mock-up and installation still utilizes nothing more then a 3" hole saw. With that in mind, we try to make every stage of building the manifold, from mockup to welding as easy as possible.