Have you had the coolant temp sensor checked? It might be that the engine is running hot but the sensor isn't showing the temp is hot.
Engine is overheating, faulty gauge, faulty temp sensor......
They don't have fuses. The speedometer is controlled by the speed sensor(s) and the temperature gauge is controlled by the coolant temperature sensor.
It's in the instrument cluster.
A short between the heater switch and temperature gauge.
Somewhere between 180 and 210 degrees but no hotter.
There's probably 1 for the cluster. if it's acting up, check sender.
If it reads hot after the vehicle has been standing overnight, it is dead and needs replacing.
Try checking Fuse #7 10amp under the dash. This is for a 1997 model.
In my experience with my Chevy it was a ground wire
Trains Unlimited - 1997 Steam Trains was released on: USA: 27 October 1997
Ground the temperature sending unit and the gauge should go to hot. If it does not the the gauge is defective. The instrument cluster will have to be sent off for repair. had the same problem, check for bad fuse located in fuse box under the hood on drivers side.
It will bolt up, but the manifolds, flywheel, wiring are different. Also the 1997 head does not have a hole in the rear for the temperature gauge sensor.