56 Vacuum Test`

[Don Owen]

My dumb Question is how and where do you perform a check of intake manifold vacuum pressure on a '56 dual quad engine. I see no fitting on the manifold which could be removed and used for this purpose. These engines of course do not have vacuum advance distributors. Please help. Many thanks. Don

[Bill Clupper]

Re: 56 Vacuum Test`

one way would be to temporarly install a hollow stud like the early pass cars used for Dist vacuum

[Richard P.]

Re: 56 Vacuum Test`

On my 2627S carb there is a brass plug in the rear of the cast iron base. I replace the plug with a 90 degree adapter. The adapter goes from pipe threads (male) to a hose barb. I can then attach the hose from the vacuum gauge to the adapter. Good luck. Rick

[Don Owen]

Re: 56 Vacuum Test`

Thankyou Fellas: Any other ideas?

[John H.]

Re: 56 Vacuum Test`

I use a vacuum fitting screwed into the base of the rear carb - Paragon sells them - #PR-755 - leave it in all the time with a plastic cap on it. Can remove for judging easily, as the 1/8" end actually unscrews from the 1/4" NPT fitting body; you don't have to raise the carb off the manifold for clearance to screw/unscrew the fitting.

John