Review on K&N Cold Air Intake Kit for 2001-2007 Chevy/GMC Heavy Duty 6.0L V8 (Silverado 2500, Silverado 3500, Sierra 2500, Sierra 3500), 57-3031-1 - Enhanced Performance and Increased Horsepower by Juan Castillo

Installation of the 57-3031-1 system was easy and did not require modification/cutting of the factory fan shroud as instructed. You'll hear a raspy difference under the hood even if you don't have many mufflers in the back. The factory whistle is almost silent, and hanging from it is a giant dingle berry, the size of a shoebox. You will definitely free up space under the hood, buy a Dingle Berry Pull. I can see the belt tensioner and could probably replace the serpentine belt without removing anything. Not that going for that sexy air intake system would have been a huge selling point. But now if you went outside and removed your factory chimney, you would go to a dumpster and throw it away. You don't want to be seen driving this thing around. You would just drive around with a bare throttle body until this amazing piece of pipe came to you. Do not add additional red/purple oil. The extra oil will bind, coat your MAF, and then you'll get the MIL.