Is there a vacuum canister for heat/ac?

[Fern]

I read through some old posts but none of them answered my question.
on a 70 challenger 440.
Where the vacuum line goes through the firewall, is there a canister to hold vacuum or does the line just tie into the carb?
Thanks

[Chryco Psycho]

no , the vaccum is sourced with a hose to the engine