EPILOGUE:
I decided to use 1/4" NPT outlets adapted to the 5/8" hose fittings on both sides, just out of paranoia more than anything else:
I also installed a regulation universal type 5/8" hose quarter turn heater valve on one side as well. Although I didn't go so far as to do so, it is the type that will work with a push/pull cable (like a choke cable).
I also chose this time to drain out the straight distilled water with Water Wetter and put antifreeze in her (with a fresh bottle of WW). Rascal took over 3 gallons of pre-mix!
I let her get warm as she would (which wasn't very warm, really - the Griffin is doing the job!), then decided to turn on the valve in the heater hose and pray that the existing core wouldn't leak.
Knock wood, I didn't detect any leaks.
Further, I went ahead and tried to get the heater controls to work enough to blow warm air at my feet (first time I'd actually turned on the fan - not kidding).
With the car still running, I really didn't hear the fan until I ticked it up to the highest setting.
Not sure what that means....
The heat/defrost selector cable wasn't really working well either, but...
Anyways, somewhat warm air sort of came out the floor outlet eventually as a result of my finagling the controls.
It isn't as the factory intended, but it just might allow me to drive her a little in the winter to come.
Here's hoping.
I declare the experiment over!
