Craig is right, I have the A/C removed from the car but still have the A/C heater box. Just in case I ever want to reinstall A/C, which in South Texas, just might not be an option.
There can often be two cannisters, one as a vacuum reserve and one is a charcoal cannister to nuetralize gas tank fumes. The metal line on the firewall is a gas tank vent and you should not plug it unless you have a vented gas cap. You will also need vacuum for your tranny modulator, and switched vacuum to your heater control valve. AC cars have vacuum controlled heater switches.