Control "What Temp Air goes Where"
Advanced Search for Vacuum Pods Yielded:
http://www.peachparts.com/shopforum/search.php?searchid=5872167
(A lot of that is not pertinent,you'll have to play with it to Narrow the Search)
I'm confident,once you've a Vacuum Diagram for your Chassis...
And the FSM [Factory Service Manual] on CD you'll be able to "Configure"
your HVAC air delivery system to your Comfort.
(Hint: You're driving a "Gasser",When you "Stepped on the Gas"...
you Increased the Vacuum delivered from the Intake to the "Users" (I.E. "Pods",Brakes,Etc.)