Thank you, much appreciated!The second photo is a vacuum retard. The one on the left in the first photo is a vacuum advance.
The rotation of the distributor is CW (looking down at it). If the vacuum on the diaphragm pulls the contact plate CCW, it's advance. If the vacuum on the diaphragm pulls the contact plate CW, it's retard. In addition to a single advance or single retard diaphragm, some Toyota distributors have two (aiding) advance diaphragms, and some Toyota distributors have an advance and a retard diaphragm. It depends on the year and the market.
Obviously, you want vacuum advance, but the vacuum has to come from the correct location and be appropriate for the operating condition.
What is this you speak of? The vacuum advance on my 78 is plugged up. A new OEM dizzy is not cheap... And not sure I want to go with Cardone aftermarket.Just had 4Cruiseres rebuild my dizzy with new vacuum advance and it is truly a work of art and professional in every way.