Has anyone done this and if so ho hard and what were the gains if any? It seems that you would get 5-15 rwhp and some mpg gains as well.

 

dont know about ALL THAT rwhp gain, i installed the FAL270 kit, unbeatable quality kit, the install was a MONSTER... half my engine bay still has blood on it from cutting myself... i did the install over a weekend in JULY... outside on BLACK asphalt... since i have a lift kit... i did everything with 1 foot on my front tire, 1 foot on my bull bar... and my upper body bent into the engine bay... i lost about 20 pounds that weekend, the wrapping, heatshrink, wiring, taping is grueling.

but it looks great, truck feels lighter for sure, way open engine bay now definetly do it again... check my gallery

 

Well, the electric fans are simply there to pull air thru your radiator when forward motion isnt enough. The gains all come from the removal of your clutch fan. If you want to see how that feels just follow the many write ups on this site, remove the factory clutch fan, and then take the truck for a spin to see if you can tell that the engine seems to move the truck a little better. The efans themselves are fail-safes against overheating.