Question about my temp. gauge!!

Nobody knows. The factory temp gauge is notoriously slow and not really tied to reality. By the time it tells you the engine is hot, you will know it in other ways, like the steam billowing from under the hood.
Buy an IR gun; it will tell you what you need to know.

BTW;
since we're talking, the thermostat sets the MINIMUM temperature, by CLOSING when the temp is below it's set point. If you have an overheat problem, either the stat is stuck in some position other than open, or you have an efficiency problem.
If it happens at speed, look to a loss of coolant, a lack of circulation, or a plugged up rad.
If it happens while idling in your driveway, look to everything, lol.
Such as;
a missing shroud, a crappy lo-efficiency fan, a slipping belt, a plugged rad, a faulty fan clutch, a really crappy waterpump, or retarded ignition timing. Not to mention a plugged exhaust, but that never happens on our classics..... right?
Your rad when the system is working right , should be able to pull the temp down about 30degrees from inlet to outlet.