3.08:1 for a standard N/A V6
3.07:1 is for the 5.0L V8 and the Super 6 LSD as they use the M80 diff
You can get 3.45:1 or 3.73:1 Get the 3.4's if you want to do alot of hwy driving or 3.7's for great take off speed. You can get 4.11:1 but you'll need aftermarket speedo correction as the PPK can only be adjusted to suit the 3.7's, just. In an auto you'll be reving around 2300 - 2400rpm with 3.7's at 100kmh.
Jezz