Just bought a supercharged 06 GT, and I was wondering what supporting mods would be required for a 3.5" pulley switch. I was considering a 3.4, but I from what I've read, it would need a fair amount of supporting mods over the 3.5, and since I don't really have all to much in the way of money, the 3.5 is looking good. I know the obvious: CAI, cold therm, and plugs. I guess my real question is: Do I absolutely have to have a 3" down pipe? If not, what would I have to do instead (if anything at all?) I have access to a scanner, so I can readily check on my KR, no need to worry about that. Any help would be greatly appreciated. Also, where could I get any supporting mods/a swap kit? As you can probably tell, I'm rather new to this, so I will not be doing the full install myself.