I am trying to figure out which is better for performance. I have a 2005 Dodge Ram 1500 4x4 Quad, and I am looking to either get a Ram Air Hood, with functional ram air box, or a K&N Cold Air Intake. I am just trying to figure out which would be better for the engine dealing with power and gas mileage?  

Certainly the cheaper way to go would be to just get the intake, not the Ram Air hood. At higher speeds, the Ram Air will have some effect, but just driving around & at lower speeds, the CAI will probably be just as effective.

Both will probably give you mild power gains. Do you have the Hemi or the 4.7?  

Ram Air hoods are cool & all, but it's a big investment. If you're just looking for performance, I'd go with a CAI. But if  you want to spruce up the looks of your truck too, then get the Ram Air hood.  

To gain power and mileage, you would be better off installing a Superchip, and synthetic oils like Royal Purple or AmsOil. As for an intake system, depending on what engine you have, there are a lot of intakes out there that are equal or better than the K&N, and some are actually cheaper, even down to half the price! Check 3rdStrikePerformance.com. They pretty much have every intake out there....