Can anyone tell me where to look for the vacuum line that runs to the HVAC controls? Or better yet, a picture? Now that I have my heat hooked up, it would be a nice touch to be able to choose which vents it blows out of.

I have a little black plastic line on the drivers side firewall that looks like it originally ran into the vacuum canister on the firewall...? However that line looks like it runs into the washer motor, or just behind it?

IIRC I tried hooking that up to a vacuum source and it made no difference.