Without going into a long diatribe about how sending units and gauges work the simple answer is "yes" if you want it 100% accurate, or "no" if you can live with the gauge reading 10 degrees or so below the actual operating temp. The new gauge will probably be way off on the low end, but around the 180F operating temp it won't be too bad. Best way to check it out is to get the truck up to operating temp, then swap gauges and see how close the reading is. As long as you know the delta you'll know when there's a temperature related problem.
I'm sure folks on here have done just what you propose, so hopefully they'll chime in.