Hello,
I am looking for an intake manifold vacuum fitting for a 1978 Buick 231 V6.
Also came on ‘77 through ‘79 231 V6 engines, and probably many other years as well.
I'm looking for either the two-port version, (see attached picture), or the three-port version.
The three-port version from an A.I.R. car.
Thanks for looking!
DAP

 

Some auto supply stores(NAPA) sell air hose fittings. It appears the threaded part is 1/4 inch pipe thread. You may be able to get the fitting with one connection on it , then add another with different hose taps available . It doesn't have to be exactly as the original as long as it allows the vacuum to the places required.
Should not be too difficult to come up with something that can do the job.. There are many options and available vacuum fittings to make a better one that will do the job.