I had the stock airbox when I was on the street tires, but I did change them to another street tire (Vredesteins) on the stock rim. Now I am running the Arrington CAI. I never had the canned tune, I had mine installed, and tuned by Josh at HHP.I have the 3.2 pulley that came with the kit. Are you running your stock airbox and thermostat? Did you use the magnuson tune that cam with it? Very impressive times you are running. Were the 20' street tires rolling your stock SRT rubber/rims?