What are your goals for the truck, and how to you use it?
An excerpt from a performance thread I put together:
Originally Posted by colo_dually
Cold Air Intakes
There is a lot of debate about the cost-benefit ratio of upgrading the stock air filter and intake assemblies on the 6.0L. The old mindset was that the stock air filter was good to 500RWHP, and for the most part that is still correct. However once you building beyond the limits of electronic programming, you are limiting your gains by the stock box.
507RWHP was put down with 175's and the Powermax turbocharger, it was truck builds similar to this that gave folks the impression that the stock air filter can and will support builds upto that level of power. Depending on your driving evironment, and personal perferances, the stock filter may not be best for your 500RWHP build. Dusty areas, and dirt roads, situations were filtration is more important is were the stock filter surpasses anything on the aftermarket for filtration and protecting your investment.
When you look at the gains of these advanced builds being put together now. 485RWHP on an S&B intake, exhaust, stock injectors, and a Stage 2 turbo, with ECM/FICM tuning. (Only 22HP shy of that 175, Powermax, stock air box, ECM tuning only.) With the investment of a turbo or injectors (between $850-$3600, plus instalation), its pretty clear you are holding your build back with the stock air filter (roughly a $400 upgrade). There are two leading filter systems out there, the first is the S&B intake and the other is from AFE.
When you look at weather your build requires the addition of a cold air intake, look at that filtration to performance balance.
I am keeping the filtration over any performance gains from the aftermarket units right now. I find myself on too many dirt/dusty roads to chance destroying a turbo or internals somewhere along the way. I feel its the right choice for stock, to electric programming builds. Once you start swapping turbos, or injectors with the support mods, you are holding the setup back with the stock Donaldson filter setup.
Stay Away from K&N, where as folks running S&B and AFE's are having a lot of success.