I've used the search feature but could not find a reference to the vacuum line that runs to the metal fitting as shown in the red circle; assuming into the cabin, possibly for the HVAC? Other?


What is this vacuum fitting for?

 

Looks like its fitted to something brake related. Hvac line goes into the passenger footwell area, if your car is a 78' chevy conversion it really cant be anything else Id imagine.

 

Thanks for the reply Vancouver,
Yes, it is an SBC conversion; John's Cars kit out of Dallas, installed by a GM mechanic in California back in '88 - I just swapped out the motor with a built-up SBC I had moth-balled in the garage, much more get-up-and-go now...

I do have the brake vacuum reservoir canister in the front-right wheel-well where that line is fully intact as it runs towards the fire-wall and then across to the brake booster; I'm not sure how this line would correlate to the brake system but then I'm a novice with this thing still.
I should have taken a broader pic for perspective; it's behind the windshield washer reservoir if that's not fully evident.

Best, Steve

 

Your car is arranged differently they changed alot from 88 onward so its hard to place certain things for me from 1 pic. I suppose you could always tug on the line until you find the end.

Thats how I discovered a huge awful carbon canister system by pulling on things haha, all part of the fun.

This site has great diagrams aswell of every system aswell.