What is this thing?

[magwakeenercew2jh]

Edlebrock Performer intake manifold with this little square thing that has what seems to be an about six inch tube that swivels around in the middle of the square. The (approximate) 1.5 X 2" aluminum square is bolted down to the intake manifold where I seem to remember some EGR stuff went on a previous motor. I blocked it off. I was confident enough that it was ERG stuff that I ordered an EGR block-off plate. Nope!!!! strange size...the block off was a sort-of triangle. Nice and shiny. But no go!!!

The tube coming out of this thing has a 180 degree bend on the end and had an about three inch chunk of rubber hose on the end. Which, of course, had been cut. Maybe it's related, but there's an "outlet coming straight out of the intake manifold that stands about an inch tall. Right behind the carb and just in fromnt of the distributor. There are two outlets on the thing. One has a cut off chunk of hose with a bolt stuffed in it. The other is a little smaller and appears not to be blocked off. But the smaller one would be too small for the size hose that is on the end of the "offending tube" in question.

I have this picture of when I started this project.

Does anyone know what the $%^# it is? If so, am I safe blocking it off? And also, if so, how do I safely do that? I can't find anything available that's the right size. I guess I could make something. But I don't want to block it if it has a use. Or doing so will screw something up.

I can say this: If it's vacuum, the vacuum to the distributor advance, and the brake booster are present and accounted for already.

On a related note, I can't see how, with the easy swiveling of the rod that comes out of the square block in question, there's a good seal for anything. Vacuum, oil, or water.

Oh, also, I'm running an Edlebrock carb. I don't know which one it is.

Thanks to all.