Large top hose goes to the valve cover.
Smaller lower hose goes to charcoal canister.


Let me know if you need any more help. I also have the Chevrolet shop manual.
I'm off racing shortly so might not be able to respond until after the weekend.
Mike.

 

TY. A few other things are missing from the equation If you had a automatic, on the firewall close to where the transmission dip stick would be is a bracket for a relay that takes a 4 pin weather pack connector that is missing and the white connector is hanging in the breeze. What is that??? There is two ports on the rear of the plenum. One goes to the fuel pressure regulator and the other goes to the HVAC. The HVAC one is plugged off and I can't find where it goes. Also, on the passenger side, there is 2- what looks like 1/8th inch black plastic vacuum lines. One of them is just hanging. Also, the vacuum to the cruise control is not connected. Where does that originate? You've been a great help. Thanks again.

 

Here is a picture of mine.

As it is a non AC, non cruise, 5 speed it may not be much help. The front port goes to the fuel regulator, the rear is plugged. The unused connector at the base of the rear runners is for AC. If you have an AC car, it is my understanding that the HVAC controls are vaccum actuated.

Mine was one of the first 1LE cars and built for a GM Motorsports racing series, hence the yellow paint sealing the engine components.
Mike.