If you plan on adding performance to your street machine or building a serious racer, Harland Sharp Original Series roller rockers are recommended for you. Using the very latest manufacturing technology and only the very finest materials, the Original Series rockers incorporate race-proven enhancements, such as improved strength, performance, and lighter weight over conventional rocker arm designs. Don't settle for any old rocker arm--go with a true leader in roller rocker arm technology--Harland Sharp.