I know its a common problem. This is not a new problem but one I need to correct. First, I have installed the additive "Water Wetter". Next step was replace thermostat to 160 degree. Next step was replace with Flex Fan. None of these helped. I still run in traffic at 230 degrees or better. If I get on interstate at speeds of greater tha 45 MPH, I cool back down to about 200 degrees. The final step is to install a pusher fan. With so many sizes and CFM options from Summit, they would not recommed one. I am thinking the P/N FLX-119, 16", 2300 CFM. But what the hell do I know? Can anyone help me with what would be the correct pusher fan? Thanks alot guys and best regardes, Steve.