Chrysler 400

On who’s gauges? Aftermarket gauges?
FWIW, I have 2 automated gauges that read 20* difference.

What is nice about your post is that you gave info with your heat gun. At the thermostat and at the radiator. The temps are low enough at the other spots that I would not worry about it. Even more so since the temp of the thermostat is very close to the other temps found. That says to me it is working and the block is only a few degrees warmer. Which that temp needs to work it’s way up to the thermostat.

I’d say your good. And the high temp spot could be an air bubble, bad sensor.....