A/C Heater Box Modification?

I assume it will work. I have seen quite a few heater/AC boxes on here that have been stripped of their AC components. I removed all of the AC components from my car, sealed the AC vent off of the box, and screwed a plate into the firewall to cover the AC line holes. I think you just have to keep a working valve to turn the water flow on and off for the heater core. I kept the vacuum activated valve on my inner fender, but you could also just put on a manual valve in the heater hose line.