Use a clutch fan! place fan half in and half out of shroud. (very, very important) The "tip flow" will be stopped if too far in and overall airflow will be greatly reduced. Too far out, you get side suction. no good either. Shroud inside diameter needs to be real close to fan outside diameter. You can be back as far as 2" from Rad. There is a dead zone in center/hub of fan, sometimes back a little will help this dead zone collect more air, But following what GM does now a days, distance wise, is a good idea. There are many reasons fans and shrouds are different on modern vehicles: inhanced cooling runners in engine, aluminum parts, cost, space, engine oil coolers, high speed water pumps and many have thermostat controlled electric fans. The full shroud did not do THAT much! For our old trucks, A GOOD MULTICORE RADIATOR and a properly located shroud is all you need. If it overheats after that, somethings wrong with pump, thermostat, timing, engine full of crud, or you live in Arizona.
Last edited by bartamos; 07/14/2010 10:44 PM.
