I tried a 36" long heatsink style laying horizontal on a 700R4......didnt work as well as I had hoped. Part of the problem is that the air flow underneath a car can be non existant in certain locations. Also, the exhaust under the car doesnt help with the ambient side of the heatsink. The heatsink coolers work well in vertical applications or, like some of the dirt cars, out in front of the car in the moving air. I tried a high volume boat bilge fan blowing down the heatsink....didnt make much difference. Now I have it in series with a Derale cooler with an integral fan.

mike in tucson