THe guides I have found show 3 used hoses:
1 to thermo vacuum valve
1 to 3 way fitting
1 to vacuum valve near winshield

And the fourth hose is for??? The schematic I found doesn't show a fourth: http://www.ultrahot.com/vacuum/engine.jpg



PS - I ordered new motor mounts, new engine dampeners and engine shocks for a final attempt at fixing my rough idle (already adjusted valves, new injectors, new dampening screw with adjustment).