1978 Cobra Vacuum Ported Switch Question

Help needed. I’ve done research on vacuum port switches. My understanding is, they get to a certain temperature (unk temp), they open and vacuum is introduced to whatever they are hooked up to.

I see 3 different type switches on this stock intake. One 3 port and two 2 port. The 2 ports are next to each other but physically are shaped different at the top. Is there a difference in all three switches? Do they all get heat from the water source through the intake water ports as opposed to exhaust ports?

I’m not a mechanic and I’m trying to figure this out.

In advance, thanks for the help.

Thanks for your reply, makes sense. I’m trying to put all of the smog stuff back and I’m trying to connect all it’s necessities as they should go but not sure where they all go. I’ll keep researching.

Thanks again.