Something also to remember.................the sending unit for most gauges is located at the front of the manifold, right near the the top radiator hose outlet . So as the coolant passes the sending unit, it is picking up the coolant at its hottest point. But it is coolant that is leaving the motor, not whats in the motor.
If the pump, rad, and fan are all doing there job, the coolant temps coming back into the block at the bottom hose should be 15-20 deg cooler.