Well, I did just call my mechanic and he told me that if I read the water at the radiator at 185 it was likely close to 200+ in the block. The rad shop determined that the one I have is not moving all that much water/coolant. The gauge is original to the truck and mechanical...so yes, I need to replace the gauge/sender too. My shop manual says that once the truck over heats that the sender/gauge need to all be replaced.
