Keep in mind I'm a huge proponent of K&N Air cleaners and have seen positive results in many applications. I bought one for my truck just today. Or yesterday. Whatever. But the other day I was going through Car & Driver, and in the back they had a series of adverts, as they tend to. One was for K&N Cold Air Intake kits... the one for C/K trucks claimed a 17HP boost. Are these significantly better than the stock airboxes? I know GM usually makes pretty good airboxes, my old Buick essentially had CAI from the factory and it was really only worth going to true CAI if you had the Supercharged car and had opened up the exhaust a bit as well (mine is naturally aspirated and only got a low-restriction muffler a few months back). But essentially, do these large aftermarket cone filter kits reap significnant gains when stacked up against high-flow oil-doped air filters in the stock airbox?