My 1977 Coupe Deville 425 has a 4-port Thermal Vauccum Switch mounted
in the front of the engine that operates on a heat signal from the
water jacket.

The TVS has 4 ports:

1. line from ported vacuum in Rochester Quadrajet.
2. line from port diectly into intake manifold.
3. line directly to EGR valve
4. line directly to vacuum advance unit on distributor

How are the two different vaccuums routed to the two vacuum actuators
inside the TVS itself?

Thanks for your help.

Tich.