This billet aluminum distributor clamp is a clean way to dress up any engine.  In addition to looking good, it has a practical side.  When you set your timing, you can scribe a mark in your distributor casting where the timing is set to align with the marks on the clamp.  In the event of a future need of timing adjustment, you will have a reference point.  Note: This feature will not work with points, as the points will wear, causing timing and dwell to change.  If you have electronic ignition, it is a super handy feature!