I looked at my '68 but cannot see any spacers. Maybe they are hidden. If you want I can use a snake camera to see if I can find them from underneath. However, maybe Illustration 11 here will help: http://www.teufert.net/partbook/67-76/6-i.pdf

Edit: I looked again tonight with the snake. I saw, what I believe, is the spacer you are questioning. It is between the larger bracket (#20 in the dwg.) and the pump just like the drawing shows. I don't think that bigger bracket has ever been off my car.