If I lowered the idle enough for the vacuum to be in the sync tool's range, the engine would not run. It was idling at about 1,100 RPM's. I was following the service manual for adjusting the idle mixture by turning the idle mixture screw in until it reaches the highest RPMs, adjust idle speed with the stop screw, back it off 100RPMs, turn the screw back out 1 1/4 turns, and readjust the throttle stop screw back to 1,100 RPMs. I did this with a bench sync and no dice. Once I built a manometer with a higher range and synced it, it was still running bad so I reset the IMS back to 1 3/4 turns out and am trying to figure out the problem now.