I could never get decent heat in the truck in the winter, and the operating temp was all over the place depending on outside temperature. So I took the fan and shroud off and mounted a Flexalite 15" fan in front of the radiator on some bracketry I made. I used the Flexalite controller with one of those capillary sensors in the radiator.
Now I know that mounting an unshrouded fan in front of the radiator is not as efficient as running a shrouded fan behind, but cooling efficiency was not a problem.
As it is, the fan doesn't turn on much unless I am idling, then it will cycle on for about 10 seconds every minute.
Here's the install details, on another forum.
http://forum.73-87chevytrucks.com/sm...?topic=27899.0