These beautiful new aluminum shaft-mount roller rockers are perfect for your small block (LA) engine. The bronze bushings provide a friction free environment for the rocker to pivot on. The system is designed so the oil comes up through the shaft and into the rocker underneath the bushing. Channels and holes in the bushing allow for the oil to lubricate the pivot area. The race-proven roller tip not only unleashes horsepower, it also lengthens valve train component life and reduces wear and tear on valve stem tips. Precision machined to insure consistency and ratio accuracy. The adjustable push rod tips allow for precise lash adjusting. 16 aluminum roller rockers, hardened shafts, and spacer hardware included. Use your stock bolts to attach the shaft to your cylinder head.