While I have the head off my engine I want to fix the crazy temp gauge,the stock one doesn't seem to be 100% accurate so I want to put in an aftermarket one so, will I run into problems if the stock one is unplugged?Can I leave it as is and run a new sending unit to the block drain on the drivers side and have two working guages? I like to know how hot my unit is running so 2 gauges would suit me fine,has anyone done this?It is a 89 22re

 

I would think that if the threads match the aftermarket sender it would work fine. thats how I did on my old chuvrolet 350 block.
You could also get a piece of stainless pipe and weld a bung on for the sender, then cut/couple(sp) the hose going into the rad
I had that set up on my old Volvo w/ 302 conversion and it seemed to work pretty well.