Mechanical temp gauge question

Hey guy's, I bought a set of temp/volt/oil gauges and started the install. I got the oil done and volt done but ofcourse the last one will not fit LOL.
The bulb will not fit in the hole where the stock temp sender is. The intake is a LD4B. Now is there another spot that can be used? I see on the drivers side rear of the intake just beside the back of the carb is a larger port. What is that? and could that be used for cooling?
Any ideas please?
Thanks
AL