Has anyone used an inline adapter to install a temperature sender?

I am wiring up my Spal efan controller and elected not to tap the factory CHT sender because a few folks were having problems with being able to program their unit properly afterward. I thought a Spal temp sender would be a better choice but I am having a hard time locating an adapter of the correct size to install it in.

Anyone have any other thoughts? Anyone know the ID of our radiator hoses?

 

I purchased another Ford sender and plug, and installed it in the block drain on the pass side. I haven't connected it up yet, but i am hoping for the best.

 

Not a bad idea; I never gave that a thought. Do you know the size / thread of the hole? 3/8" NPT?