[supereal]

Six bladed fans were used on large trucks. They are noisier, as mentioned above. The stock fan should be adequate if your radiator is clean inside and out. This is the main reason for overheating in the majority of cases. Good radiator shops are scarce, and it is the often better to replace rather than try to fix the old one. The fins often separate from the tubes, and an interior coating of lime the thickness of a coat of paint will reduce the efficiency by half in some case.