Newb & geezer -- I found a product for a fan temp sensor that fits in the radiator hose... It even has a small screw for connecting a ground wire...

Install VIDEO here: https://www.youtube.com/watch?v=X1J_SgpgV68

Someday I will look for those intake manifold spots geezer pointed out; a threaded temp sensor in an OEM spot would be great...