I just purchased a 2010 Inferno Orange SS/RS, it has 10,100 miles on it. the previous owner drove it 2K each year. at 5K miles he had the dealer install K&N CAI, JBA Pacesetter 1 3/4" headers and Magnaflow Cat back, He also had it tuned? This is my first LS3 so what do you all think this thing is making for HP? 10HP Increase 20? I have had other performance cars that I have dynod and they all take to bolt ons different.