Thermostat not working ?, Engine running hot Options

[North Coast Jim]

Drove about 50 miles at ambient temps of 90 degrees. All flat terrain. Turnpike driving at 75 mph. Engine temp continued to rise approaching red zone. Slowed down and over time temps stabilized. Still high in my estimation. I only have the temp gauge in the console. The std gauge.

Took a picture of the thermostat cable and flap connection when I got back home. Reviewed it with a cold engine and compared. The flap control isn't moving. Looks like thermostat is not working as all other components work and are not bound up. This is a hard to find part. Any suggestions for where to go and purchase.

Lastly I've not yet got around to assembling the heat control in the car. I don't have the flaps on either side at the bottom of the blower housing. Neither do I have the lower heat shields installed. I do have the cylinder shields installed on the bottom. Do these components effect engine cooling ??

Appreciate any and all help. Want to get this fixed before Octeenerfest.

[ericoneal]

My thermostat works partially, but does not open all the way. The engine was getting very warm after an evening drive, so I loosened the screw on the flaps, then they completely popped open. May be what you are seeing here..