Ok, so I am putting the new non-ac box in the car. In order to do that I had to yank the hardline section of coolant tubing to the heater core. I planned to do this anyway, so not a problem.
First - I am *considering* totally bypassing the heater core and running a straight tube from my water pump to the radiator return. I'll have to make that call tonight.

Second - no matter what I decide to do, I need to get rid of the vacuum line correctly. The one I am talking about connected to the in-line valve for the heater core. Where does this vacuum line go? I assume to the heater controls in the dash.

How do I properly get rid of it?

Does getting rid of this valve and routing the tubes for constant flow mean that the heat will always be on?

 

Well, the heat would be "on", but it won't be blowing at you. Coolant will just be allowed to go thru to the heater core.

This easy-to-crack Heater Diverter Valve started in '87. My '86 didn't have one. I replaced those factory steel lines with regular 'ol heater hose, and coolant's always flowing thru the heater core. The inside car temp might be a few degrees higher, but no big deal.

I'd say to plug the vac line up with a golf tee but I think you want something more technical