Thermal fan switch and thermostat combo

[MYOUNG]

I Just finished installing my electric fan conversion on my near stock 69 GMC 2500. I used the 1995 ford Taurus fan with a single stage controller kit from Amazon and electrically everything works great. My question has to do with the correct temperature of the Thermostat VS the Thermostat fan switch. Currently I have a 160F thermostat and a 185-170F fan switch. The problem I am seeing is that once the fan comes on, it does not really turn off. I would like the fan to cycle as needed and not run all the time because the cut off is close to the Thermostat temp. What temperature fan switches / thermostats are you guys using?? I have seen 190-185, 200-190, 195-185 etc.

The fan switch is currently mounted in the 3/8" port at the front of the intake

BTW I managed to use my original fan shroud with the new fan. I rear mounted it from the inside with 1/4" spacers and still looks stock. There is about a 1/4" gap between the water pump pulley and the fan motor.