I've been looking into an UD setup with the efan. and i've combed the entire site for feedback and reviews. and its half and half. im on a 6" an 35s, and one post i read said that bigger tires hurt the UD's. I'm just tryin to get a little more power and economy outta my truck. an also if i bumped up the idle on my edge. would that help the "lack of power" to the alt. like i've heard?

 

what gears are you running???

 

I never had any issues and only removed my underdrive pulleys in favor of a supercharger, but at idle when you turn the wheels you'll hear your power sterring pump straining, honestly you probably ought to look into some box long tube headers and leave your pulleys stock

 

I have stock 3:73's right now. But I'm looking to go to 4:56's. Cause when I regeared my old truck, it was the best move I've ever made. I really want this new one to be able to move though.