This shaft mount aluminum roller rocker arm kit from COMP Cams is designed for Chrysler V8 273-360 applications and has rockers with a 1.6 ratio. Mounted on an ultra-durable shaft, these rocker arms are made from a high quality aluminum alloy with a tensile strength of 80,000 psi. Needle bearing trunions allow value spring pressures of 350 pounds open pressure, making shaft aluminum roller rocker arms good choice for race applications.