Using COMP Cams Shaft Mount Rocker Arms is one of the most effective ways to increase horsepower. The rigidity of the shaft system adds stability to both the cylinder head and valvetrain. By properly positioning the rocker over the valve, it's the most efficient way to transfer the power of the camshaft to the valve. Rockers are constructed of 2024 aluminum and shafts of 8620 hardened steel. Shaft rockers use an oiling system that assures consistent flow from the pushrod cup to the shaft bearings and then to the roller tip.