Here is the detailed info Q, John and Bjorn are talking about:
http://www.wallaceracing.com/water-pump-mods.php

A good idea to have this set up right no matter what... can't hurt, and you know for sure your set there! My Stock gauge was way off too, faulty sending unit, and old gauge... I got a liquid filled Therometer that installs in the intake manifold, so I know for sure what temps I'm at, and it was 190 the whole time.
http://www.jegs.com/photos/55541000a.jpg
http://tinyurl.com/5z2lq for the description. They are usually $30, but sometimes are on sale for $20.

Perhaps the gauge is off?

Good luck - Brett!