I was so tempting to turn the boost up a bit and lean out the AF to 12.5 so I can break 550rwhp...but...those 555 might not keep up :( Good luck on your set up man! 650rwhp musta be crazy fast! I felt like I was rear-ended by a highspeed train when I ran the car on high boost first time. Crazy...just crazy....
I am running colder ngk platinum and the car has 56k miles.