Helping out a buddy. He has a sb w/stock shroud and radiator but an electric fan. Temp has been okay since rebuild about 10K miles ago. Now, when he is idling, the temp comes back down to normal, but when driving the temp gets into the red zone. He changed the thermostat, flushed the system, and put new coolant/water mixture in. It's slightly better, but still overheats when driving. This is a weird problem. Whenever I have had overheating problems, it usually gets worse as I slow down and idle is the worst. His problem is showing opposite symtoms.

Any suggestions or comments appreciated.

See answers here... http://www.camaros.net/forum/ultimatebb.php?ubb=get_topic;f=19;t=000172