A QUICK QUESTION ABOUT MANIFOLD VACUUM

Well, I cleaned the hell out of it and blew out all of the passages and installed a new kit and adjusted it to the OE specs. It actually looked really good when I first received it. It was a late 70's take off from a Barracuda and then shelved. No evidence of dried fuel or varnish. LOL...It was delivered in a '70's Holley box so I can imagine the story.

BTW....Pardon my ignorance, but what does IFR stand for?