You are not going to see a noticeable HP gain if your stock fan clutch is operating correctly, as the electric fan takes power from the alternator which is still driven by the engine. It is generally regarded as inneficient to use two fans, as one is going to restrict the other. (ALthough second gen autos use two <img src="/forums/images/graemlins/confused.gif" alt="" />..., I thinnk one is for the AC condenser and trans cooler) Do you have cooling problems now? Do you need you engine to run cooler? I would look at obvious things like fan clutch operation , thermostat, gunk in cooling passages and or radiator and corroded radiator fins. I am not bagging on the electric fans I just don't think they are all that great a deal.