Timing problem

11* is really low for a 318. Even if it was running really retarded I can't see it being that low. But bring her up to 10* advance, and read the manifold vacuum again,if you can. Actually, I would just start her up and tug on the Vcan until it stays running.
IMO,It won't idle cuz the engine is pulling in air somewhere that has no fuel in it; ie a vacuum leak, and at that low a vacuum, the PV may be dumping fuel. You will need to clamp all known vacuum taps; like the PCV, the booster, anything running off vacuum. If that doesn't improve things, then we move on to the carb secondaries, the carb base, the intake manifold topside and then the bottomside.
If you can't keep it running no matter what and the vacuum remains low, then I would go straight to checking the cam-timing.
I've seen a few jumped chains manifest just like yours.