How to purge motor with oil on fresh rebuild before starting on 1980 shovelhead?

To purge the motor with oil on a fresh rebuild of a 1980 Shovelhead before starting, first remove the spark plugs and then use an oil pump priming tool or a drill with an appropriate adapter to circulate oil through the engine. This will help ensure that oil reaches all critical components, including bearings and the oil pump. After priming, inspect for any leaks, re-install the spark plugs, and then start the engine while monitoring oil pressure to ensure proper lubrication.