One issue at a time,
Washer between the distributor and block? Big flat washer looking thing? I am not sure what you have.
Cast drive gear on a forged cam will wear fast. Forged gear with a cast cam will rear the cam also fast. Match the drive gear to the cam.
Which distributor you have can be determined by the number on the label on the side of the dizzy. There is a Good post on the dizzy part numbers on here some where. I just can't remember where.


Steve H