help visous fan worth it or not???

A fans purpose is to draw or push air thru the radiator while at a stop or at slow speeds. Once a car gets up to sufficient speed forced airflow thru the radiator will cool the engine. Stock fix bladed fans and flex fans are driven by the engine at all times and waste fuel and hp once the car is above the speed needed to provide enough airflow. Electric fans use no HP as they are, of course, powered by electricity produced by your alternator. They need to be controlled (turned on/off) either manually or by one of a number of types of temperature sensing switches. Viscous fans use a temperature sensitive spring which when heated engages the fan, at all other times it freewheels. A shroud should be used with any fan to improve airflow and efficiency. My pick is for a clutch fan for simplicity in installation and out of sight out of mind operation. Try looking at a unit off a Jeep product with the fuel injected straight six out of a junk yard or purchased new (fit perfect on my 65 Cuda).