For Moderate to High Performance use, Manton Series 3 pushrods are made from hard drawn 4130/4135 seamless chromoly tubing originally formulated for aerospace/aircraft use, the highest quality available from mills. They are a higher quality pushrod which provides approximately 170,000 psi tensile strength. (Note – Shaft or pedestal style rockerarms should be used in conjunction with this series of pushrod because we do not case harden the tube for guide plate use.)