I also have autometer gauges (and love them
)
I have a stock 350 with 4-core rad and 195 thermostat.
I also run a dodge/jeep factory electric fan for v-8 engines.
Most the time the fan isnt on.
Even when the fan is on it acts the same as far as temp changes and low/max readings).
First thermostat cycle of the day it gets up to around 210 degrees then lowers down to 170 or so. After the first cycle its anywhere between 180 and 195. You can actually watch the needle go from 180 up to 195. Right when the needle hits 195 it drops right down to 180 and starts over again.
If I shut the truck off and come back out in a minute or two then it gets up to 220 degrees.
The gauge is accurate and shows all temp changes, you really cant ask for more.
I replaced my thermostat this weekend along with a few other things and noticed the reading got up to 230 or so before the thermostat opened up for the first time. After that "break in" it was acting the same as before. I suggest you keep the 195 thermostat.