Adapter Rear Cylinder Heater Hose Help Needed

[S11A]

Ahh, thanks that clarifies my confusion.

[o2batsea]

I can't figure out what the reason for saving the old valve is. There's like ten gazillion other possible heater control valves out there that are easily adapted to your system. You'd just get a metric fitting that has a hose barb on it, then plumb the HCV in between the head and the heater core.