Join Date: Aug 1998
Location: Waldorf Md. USA
If you are using the stock GM fan sending unit, it turns the fan on at 240 degrees. Hypertech makes a fan switch that will turn the fan on at around 180. Try turning the AC on, if so equipped. That should turn the fan on at any temp. If the car runs cooler with the AC (and fan) running, then you know that is your problem. I used a 84 Z-28 aluminum radiator and electric fan on my 67 Camaro drag car for many years and could not make it run hot if I wanted to so the radiator is up to the task of cooling the 350, as long as it is not all clogged up.
Most people do not realize that the new motors are run that hot for higher efficiency.
Hope this helps,
Advanced Automotive Machine