PRP Racing Products’ Big Block Chevy Stud Girdles are the answer to securely holding your poly locks for precision rocker arm adjustment. All girdle kits are available with, or without 7/16” locks. We are offer two styles to fit your engines cylinder head configuration. Stock bars will work for any stock rocker arm stud location, while aftermarket bars will fit – Airflow Research, Bowtie, Dart, and Melin heads with moved rocker arm stud locations. These bars are machined from 6061 billet aluminum and machined to a bright finish.