The electricity to power a electric fan is made by spinning the alternator. Takes power to do that. There is no free lunch.
99% of the electric fans do not pull enough air thru the rad to keep a V8 engine
cool. Especially a high perf engine. Get a good OEM GM 7 blade heavy duty A/C clutch fan.
Get the crank pulleys and water pump+alternator pulleys and belts too.
Don't forget the fan shroud. If the fan clutch bearing is gone, replace it.
80's GM V8 pickup or Mid 80's camaro firebird with carbed 305 V8.