The Stovebolt Site Forums The Shop Area Engine Shop Intake Manifold Hole

In this picture, what is the large hole in the manifold to the left of the bell crank for?

I'm guessing vacuum port for wipers. You don't mention year or engine.

It goes on 250 motor that I have installed in a '56 Chevy. 1956 Chevy's came with a 235 6 cyl. however I was able to fit a 250 in the car without problems.

Oh, and I've converted to electric wipers on my '56.

Just stick a plug in it if you don't need vacuum. It'll run like crap (if at all) if you leave it open.

On a 250 there may be other vacuum needed for a choke pull off anti run on Pcv ect.

I think that was the PCV connection, and it possibly had a T that fed into power brake booster. If you know what year the manifold came from, you can look at the GM Heritage documents and probably find the vacuum network. Around 1973 EGR started and it could have been connected with that, also.

This is a vacuum diagram for the 1971 250 (with 1bbl), and some may be different on yours (depending on year). But I doubt you'll be using all this stuff, at any rate...

Thanks everyone