PRW aluminum stud girdles are made from 6061-T6 aluminum, manufactured to exacting standards, and the solution to valve train instability. PRW stud girdles reduce rocker stud flex to retain critical valve lash adjustments. The result is more accurate valve lift and timing. PRW stud girdles are relieved at the factory to accommodate crankcase evacuation components without the need to visit your local machine shop. These products are CNC machined, anodized for a superior finish, and come complete with PRW RockerLocs.