My original dash cluster was in very poor condition, so I changed the dash to a front removable insert with after market gauges.

The water temp runs about 210 - 215 using the stock rear temp sensor hole after stabilizing engine temp by driving 30 mins or so, whether A/C is on or off and whether A/C condenser pusher fans are on or off. I have a 190 Beck/ Arnley 1430354 thermostat.

I used an infrared temperature gauge and measured the surface temp of the brass sender and it agrees +/- 3 degrees with dash gauge. I then measured the thermostat housing and the small removable cover with 2 bolts right below the thermostat housing and found them at 198-202 degrees. These measuring points are an inch or so forward of the exhaust port.
The top radiator tank reads ~190, the bottom ~ 160.

The exhaust manifold as it leaves the head ports are ~ 400 deg.
I then measured the opposite side of the head and found the temp about 195-200.

I think the factory location of for the temperature sensor is too close to the exhaust port and giving a false high reading.
Maybe this is why so many people complain about the stock temp gauge reading so high.

I think I may drill and tap the small removable cover with 2 bolts right below the thermostat housing, it is about 1/8" thick so not many threads.
Any else tried this?