main vacuum source for heat/ac

[86chevyk20]

SO i got my heater core back in along with the new controls and i was thinking about the vacuum lines today.
I dont have any vacuum lines that are going from my engine through my firewall.

SO what is my vacuum source for my ac/heater controls? Where do i need to connect a hose too?

Thanks
Liam

 

[89Suburban]

Should be a place on the intake manifold behind the carb. Threaded into the manifold with a nipple/nipples.

 

[86chevyk20]

i have all after market. I have a edelbroke 600. i dont know where the vacuum line is. i dont see a vacuum line that is coming through the firewall

 

[chengny]

These images my help.

Do you have a vacuum chamber? It isn't absolutely necessary but helps smooth out the controls during times of varying engine loads.

For a vacuum supply, I tee into the transmission modulator line in the back of the intake manifold. Be sure and install a check valve where indicated. Also included the tubing schematic for dash side: