I now realize that 68-69 and 70-72 Ac/heater systems are slightly different...

In 68-69, did the vacume line for running the ac go to a vacume tank or resavior of some kind, or did it get hooked up directly to the engine vacume ports?

now that i have a new heater core, new fan motor, i'm tyring to figure out how the doors inside the heaterbox are supposed to be moving- some of mine work, some don't.

Someone please correct me if i'm wrong here, but it looks like:
defrost & floor ducts are cable controlled
Center & side vents are cable controlled
Hot/Cold/ouside air are vacume controlled

is that correct?

Ben, there is a coffee can style of vacuum tank that mount to the side of the evap case. A hose goes into it from the intake manifold, and one goes out of it into the car. I'm not sure about the cable stuff, I've never had to look that deep into it. The Chassis Service Manual probably has some info on the system

BillL

For '68 you are correct, pretty much everything was cable operated with the exception of the fresh/recirculate air control that was vacuum operated.

This change a bit in '69 then I think they may have added a vacuum control to the hot water but don't quote me on that. I do know that the '69 control panel I picked up does have an extra vacuum line coming out of the panel.