I was playing with it again today. My fan is set to turn on at 195 degrees and turn off at 175. I have a 180 degree thermostat. .
I put an aluminum radiator and dual spal fans on mine, 440 in a 68 charger. At first, I had the fan relays turning on and off with a toggle switch and kept my 160 thermostat in...I finally got around to installing a temp sensor that turns on at 170 and off at 140. At that time I pulled the thermostat, cut out the spring/middle assembly and installed just the flat outer ring in the wp housing. temps much more steady now than when I had the fans on all the time and was relying on the thermostat. For my car this setup seems perfect, when I start driving, even pretty slow, the temp drops enough so that the fans are almost never on when I'm moving and don't come back on unless I'm at a light or stopped for more than 3 or 4 minutes. I was curious if you think that running the temp sensor and thermostats together could confuse things a bit.
on another note, I don't know if all 440 stock WP housings have this, but my 71 housing was from a car that had the idiot lights so I have the standard port for the factory temp gauge and I used the larger threaded opening for my temp sensor, didn't have to drill or tap anything.
