I'm going to guess the car had at least 3 vacuum operated systems.
Chrysler may not have placed all of them on the same diagram.
The underhood diagram would have the emissions related system(s).
EGR:
According to the diagram posted in
that other thread, Calf car may have had this
venturi controlled EGR system.
Reposted here with some colorization.
None of these components are tied into the distributor vacuum.
The venturi vacuum port on the carb is probably located higher than the distributor port.
Distributor Vacuum Advance:
Without any additional information my guess is the distributor vacuum advance connected to a 'timed port' on the carburator. It may have OSAC - see next post.
Another possibility is a connection to a coolant temperature control valve. If so, the temperature control valve would then have one line getting ported vacuum from the carb and another line getting manifold vacuum. The purpose of these is to switch from ported to manifold vacuum if coolant temperature exceeds something like 210 or 220*F.
Power Brake Booster:
That should be a big hose from a manifold vacuum source. On a stock 318 my guess is the connection is direct.
PCV:
PCV Valve direct to manifold vacuum source, usually on the carburetor base. Big hose.
Others Maybe:
Air Cleaner controls - if the aircleaner has flaps inside the snorkel, then there will be a vacuum hoses to open the flaps. One snorkel valve is closed when the engine is off to keep fuel vapors from escaping. Another snorkel valve is to mix in warm air. Doubt that was used in '74.
