Liquid filled thermocouple relocation
 

I replaced the 59A with a 36 21 stud in my 39 pu. The thermocouple tube is too short to reach the water pump fitting on the front of the 21 stud engine. My plan is to weld a boss onto the steel tube from the pump to the radiator. I thought the nut on the thermocouple was 3/8 pipe thread but an iron pipe coupler did not seat. Is anyone aware of an off the shelf fitting that will fit the thermocouple and seal on the flare?

Re: Liquid filled thermocouple relocation
 

The thread on the temperature sensor nut is 5/8-18 straight thread. The sensor uses a collar around the top and compression from the nut to seal the coolant from leaking. In 39-40 Ford used a brass adaptor fitting so the mechanical temperature sensor could be installed into the 81A head (with NPT thread) 01A-10889 maybe this will help your install. NAPA may have the adaptor?? Some of the aftermarket parts houses used to be able to supply it.

Re: Liquid filled thermocouple relocation
 

Terry, Thanks! I have been googling for 90 minutes, found one place "2040 Parts" advertising the 01A-10889 for $10.99. The website has one picture, no specs and does not inspire confidence to volunteer my credit card info, in me at least. Anyone ever dealt with them before?
I also tried the NAPA website, their website designer should have their balls cut-off with a spork. The search engine filters allow you to narrow the search with the same efficiency as flipping pages in the Encyclopedia Britannica.