Vacuum Diagrams for your 66 can be found at
www.tbirdranch.com.
Scroll down the choices on the left side of the home page and select:
Diagrams Index
This will open up a page full of vacuum and electrical diagrams that include:
64-66 heater/ac vacuum diagram, 64-66 vacuum trunk lock diagram,64-66 vacuum operated door locks, and 64-66 vacuum operated rear air vent.
Also provided are three electrical diagrams for the 66: the charging system diagram, emergency flasher system diagram, and sequential taillight system diagram.
Good luck.