So I did a little experiment and remembered that the late nineties ford Rangers and Aerostars with the 3.0 V6 engine used a temp sender at the heater hose outlet.
Ordered one, Dorman 47993, which has 3/8 pipe threads just like the intake where the ouput for the heater is. Also has another female 3/8 pipe to install a sender.
Bought a 1/2”x12” brass tube at ACE Hardware, so it can get down into the coolant like the original, and used a 1/2 drill bit take a hair out of Id of fitting an left a shoulder at end. Going to put a little red loctite on it and push it in. The last 1/8” has to be pressed in because I used a normal 1/2” bit, which is good.

Carl
Kansas

That's a cool find.  It could serve many purposes.
My only concern using it for a sender on a Y would be that it may result in false temperature indication if the coolant level ever drops below the sender.



Lawrenceville, GA

Some vehicles have bypasses on the heater control valve, and some regulate temperature by the airflow/air mix. Your’s will work fine in the heater hose if the heater water flow is turned on. I’ve had some cars were the heater valve always passes some water, but I’ve had others where it shuts completely off and the hoses run cold. Depends on how your heater is set up. Nice work.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I was going to drill and tap a new hole on the flat part in front of the heater outlet, looked like I could do that and still be behind the thermostat, but it took me quite a while to find a B intake for my 56 and wasn’t ready to drop over $400 with shipping on an aluminum one.
I figured like they say “you got two chances on your own crap, Slim and None. And someone saw slim saddle up and ride out of town, so that narrows it down” and I did not want to look for another after see it develop a crackdown the road.

Carl
Kansas