Can I just hack into my upper radiator hose using a T to hook up my mech water tempt gauge?

 

i dont see why not. when i was think n about installing one in my car, i was gonna cut the radiator hose in half, and then install a piece of pipe about 3 inches long, that is the same diameter of the radiator hose, inbetween where i had just cut the hose. Clamp both end of the hoses to the pipe. First u would want to tap a hole in the pipe to fit the water temp sensor. install the sensor and and thats it.

 

Absoulutly. That will work because i did it in my car a year and a half ago. Never has failed me since.