What's the big difference between the K&N Aircharger and Fuel Injection Performance Kit? The Aircharger is not 50 state legal and designed for offroad and race use, but what's the difference performance wise? I checked the website and didn't find much help. I'm asking b/c the Aircharger (non-50 State Legal) is $150 bucks cheaper than the FIPK. The Aircharger also doesn't allow for reconnection of certain emission controled devices (thank God I don't live in California!). Any help? Just starting to add to my bone stock engine, thought I started with intake/exhaust with an Air Filter and Headers.