wont turn off for anything

[angst]

84 300sd almost nothing is getting it stopped. Stop lever doesnt get it done. Ive even tried disconnecting various rods to the stop lever and pulling them individually.
Im reading 12hg vacuum supplying the shut off valve at the back of the injector pump.
Ill even seal up the intake and push the stop lever all the way and enough air is still getting in through the pcv valve hole and nut on top of the air cleaner and it keeps on running.
I did mess with the vacuum lines to the ignintion switch last week when I gutted the steering lock, but I have been under there and jiggled those with no different results. Im out of ideas.
What is the minimum threshold for vacuum? All the testing step by steps say to check for vacuum presence at various places but how much is enough?