I haven't read your other posts so I don't know the whole story.
I was having problems on my 84. It ended up being a leaky actuator on the waste gate. I just tested by blowing or sucking on it and air was getting by. The one I swapped with had two vacuum line openings. The one farthest from the arm is the one that goes to the y. The inside one can be left unhooked, but don't plug the end just leave it open. I tried it plugged one time, and thank God I still have head gaskets. It was 26 pounds of boost and climbing.