I assume this is going in a 1939?
Are you planning on converting to a 12 volt system?
If so using your "6 to 12 volt converted starter" you need a 1942-54 (or 1955 first series)flywheel. That will have 139 teeth.
If you decide to use a late 1955-62 flywheel, which will have 168 teeth, you will also need a a starter from a late 1955-59, they will have the foot starter setup.
