OG86

Ok so I am currently running a 20v blacktop in my GT-S. I bought the coolant conversion kit from SQ and a tweaked performance wiring harness. Everything was smooth sailing until I realized that the block off plate on the back of the motor only houses the ecu temp sensor and the coolant temp switch (white). I was told that the switch isnt needed..makes sense why there isn't a harness side connector for it...but it fits perfectly in the block off plate. On the other hand, the coolant temp gauge (gray) I was informed that I needed...but have no place to put it....but has a harness side connector. Main question is where do you guys have this sensor mounted, it looks to just be a signal wire going to it...just need more info on how this guy works and if I can stick it in the upper radiator hose or not. Thanks!