Manifold vacuum port question

[fmahannah]

On my max wedge manifold, they added a vacuum tube to the PCV valve connector as shown in the photo attached. They had it blocked and were not using it (stuffed a bunch of scotch tape into the rubber line).

I am trying to use this for manifold vaccum on my vac adv distributor from Summit. It seemed to work but when messing with timing I bumped the rubber vac line hooked to this tiny vacuum tube and it killed the engine like I had shut the key off? Apparently it has a slight vac leak that gets larger if you wiggle the rubber line. Line is smallest I have and seems to fit better than what they had on it.

I want to eliminate this and use a vacuum line from the carburetor, but Carter 3705s did not have any vacuum ports?

Any ideas on how to add a better manifold vacuum source to a max wedge manifold or to a Carter 3705 carb (without any spacer plates)?

Thanks

 

[4406bbl]

They make that fitting with just a single small line if that would work.

 

[fmahannah]

They make that fitting with just a single small line if that would work.

Where can I find that fitting? This one is messed up. Thanks!

 

[fmahannah]

I think I found one:

https://www.classicindustries.com/product/all-years/dodge/challenger/parts/mp700102.html

 

[4406bbl]

Megaparts has them.

 

[JoePole]

Watching. I want to add an under hood vacuum gauge. Looking for a good source to T into.
I have the fitting shown but it is used to feed my HVAC on my 72.

 

[diesel_lv]

Watching. I want to add an under hood vacuum gauge. Looking for a good source to T into.
I have the fitting shown but it is used to feed my HVAC on my 72.

Simple enough to put a "T" in the HVAC vacuum line.

 

[JoePole]

Simple enough to put a "T" in the HVAC vacuum line.

That's what I figured. Brass T fitting.
Edit.....It is a really small diameter vacuum line.

 

[diesel_lv]

That's what I figured. Brass T fitting.
Edit.....It is a really small diameter vacuum line.

I just use the plastic "T's" that come in an assorted pack.

 

[fmahannah]

That's what I figured. Brass T fitting.
Edit.....It is a really small diameter vacuum line.

Yes the one on my fitting is maybe 1/8 inch

 

[Geoff 2]

That fitting looks like an early p/brake vac fitting that screwed into the intake. If you have PBs, you can use that fitting & use the small line for VA. Or, just block off the large hole & use the fitting.
I would not use any emissions port for VA unless the port goes into the intake or it goes to a dedicated port on the carb that exits below the t/blades.
Another thing you can do is drill a small 3/16" hole in the carb base that exits in the t/bore, below the blades. Cut a small piece of brake line & Loctite in place.