Thermostat or No Thermostat?

Years ago when I built my Dart I started with a 340, aluminum heads, 11.4-1, factory pulleys, new copper radiator, new standard pump, Black Magic electric fan with a Painless fan controller. It ran hot so I bought a generic aluminum radiator from a local roundy round shop. The fan wouldn't work with the new radiator so I bought another thinner electric fan that supposedly moved 2800 cfm. It still ran hot, a new Flow Kooler water pump and it still ran hot.

I was ready to pull the engine and someone suggested that I try a belt driven fan and shroud. A buddy of mine had a like new MP viscous fan kit that he made me a deal on. I had a shroud for a 26" radiator that I cut down and made fit the aluminum radiator and fan. No more over heating, on cool spring or fall days it ran right on the 160° thermostat and didn't get over 180° on hot days or at the drag strip.

The same set up was used on my 408 and is now on my 434. The only change is a smaller diameter crank pulley that I had to use with the Innovators West aluminum damper. Even with the smaller drive pulley it runs cool. I've ran 6.40 with this set up and see no reason to change.