i have an 02' with a 6.0 and what i found is that if you have the factory hi flow air system all you will need to do is drop a k&n in but if it doesnt then you need to get any of the others out there.i bought a mac cold air.its the same as the others accept alot cheaper in price.the restriction on a factory intake is in the tube after the mas air flow sensor and any of the ones out there replace it all the way to the throttle body so check the prices and take you pick.rpmoutlet.com has 4 diffrent ones to choose from...check them out...theres alot of places to buy this go fast stuff from .....bud8..