and 175 degree (maybe 180) switch located in the upper radiator hose. My heating problems come in 100+degree weather while sitting in stop and go traffic with the ac on. I also have an upgraded oil cooler, so that could help contribute to my problem. I am thinking about going to the ford sho fan (which comes with a shoud and is 4500cfm) on the recommendation from Greg or the dual spal with the spal programmer as recommended by Seb.