[750hp]

You could leave the faulty one in place and look at something like the BE COOL range if thermostat switches that screw into your intake manifold. They make a number of temperature switching options. I have one that comes on at 195F and goes off at 185F. The fan switches on and off exactly as per the gauge readings.

My only preference would be to bump the "off" temp up to 190 as it sometimes takes a few miles of highway driving to hit 180 and switch off the fan. It's annoying sometimes to see the temp hovering at 182 or 183 for miles on the highway with the fan running...