[Zoojelly]

I removed vacuum to headlights and egr, added power brakes and trying to figure out these hose attachments, this is 4 speed car and trying to figure out small port on front of intake manifold, some say it T with line from valley pan to carb base

[Zoojelly]

Here is a current picture

[Zoojelly]

This port?

[OG68]

1. EGR? 68s didn't have an EGR.

2. The factory set up on all 68s used a 5 port thermo switch for vacuum control. It was modified to use three ports later in the model year.
Your engine has a three port thermo switch from a later model engine.
68 manual transmission cars used a de-acceleration valve mounted to the passenger side intake manifold creating a jumble of vacuum hoses for distributor advance. It would take a few paragraphs to describe how it worked.

If you are wanting to recreate the factory setup, this is how it's done.





Modified version



3. If you just want to have manifold vacuum advance, plug all the other openings except for the one at the rear of the carb thats used for the power brakes. There is an additional manifold vacuum vacuum fitting on the right rear carburetor stud.

4. If you want to use Ported vacuum use the front drivers side port on the carb.

5. The intake manifold nipple at the front is used for the factory air cleaner to control the air snorkel valve.

[OG68]

Another photo

[Zoojelly]

Thanks, that last picture is helpful, I got egr from trying to decipher from newer schematics
I may plug off the small manifold to air cleaner, looks like a special adapter needed for hose end. .
My 3 port is aftermarket
Are you suggesting ading a deceleration valve, I remember there used to be something on passenger side

[OG68]

You already have it (Vacuum valve at the rear with a black plastic cover). And unless you're doing a concours restoration you don't need it.
The only thing missing from your air cleaner snorkel are the vacuum lines from the snorkel valve to the temperature switch under the air cleaner to the manifold fitting.

[rwfisher]

.???

[Zoojelly]

What would you suggest for brake booster vacuum? I also have the large looks like manifold vacuum port on front of carburetor, is this plugged now?

[OG68]

You may have a base plate from a different year. That large port wasn't on 68 carbs. Power brakes use manifold vacuum from the rear baseplate opening. So move the PCV hose to the brass manifold fitting, and cap the opening.

[Zoojelly]

I connected carburetor advance to distributor and brake booster from the back and plug everything else.