Water temp sensor thread size

[Kevin B]

Ok so I bought an aftermarket temp guage for my 93 D1 3.5, plummed it in and ran all the wires, looks cool too, however the temp sensor that came with it sais it was 1/4 NPT but when I removed the original from the block it was much bigger looked like 1/2 " , I tried using the original with the new guage but it read 80deg when engine was cold, so obviously a sensor matching the new guage is required, what is the correct size of the factory sensor.and would an adaptor be available, it not I might have to mount it in the hose using one of these

40mm Water Temp Gauge Radiator Hose Sensor Adaptor | eBay

But which hose would be the best, inlet or outlet

[MacMan]

I fitted one of those adapters when I installed my Autron gauge on the Disco. I put it in the bottom hose to indicate efficiently much the radiator was cooling since I also have oil temperature reading from the pump. Placing that adapter in the top hose will give you more immediate info on engine coolant.

Can't help on the factory thread because I can't remember.