Question about my temp. gauge!!

Hello Mopar World, I have a 1973 Duster that I have had for 17 year's.I built a 383 &727 and put in it 15 year's agoI drive it on the street and drag race it also.My question is on the factory temperature gauge,I still have all of the original gauges in it.I added a water temp &oil pressure gauge.At what temperature is the coolant when the original gauge in the dash is at the hall way point??. My second temp gauge is just a cheapo p.o.s..and I know it's not correct. I just wanted to know about the original gauge so I can figure out if I am running it to hot, Once I kinda know this,I can go from there.I am thinking it's around 195- 210, Just my guess. Thank you in advance for any information about this.It would help me out. Everyone have a great day.