heater/fan controls

[Caddy63]

Hello folks, The SBC 355 is in place and running in my 81 regal. How about the heater fan and the vacuum for the heater controls? Do I just hook a vacuum source in to the small vac line? I assume that that will make the controls (defroster/vent/floor) diverters work. Which wire in the mess of wires I have left over needs to me connected to make the heater fan operate? Thanks, Scott