Originally Posted by Denis
I've read that the 3.70's are better for the auto than the 3.91's due to the transmission gearing.
That's pretty much what most people on the forum are saying. It would be fun to try 3.91s or even shorter just to see how it felt. It'd probably be really wild on the auto. The nice thing about upgrading the gears is that even 6th gear becomes very useable. You still have to downshift if you want that kick-in-your-face power, but you can keep it in 6th on the highway and still accelerate reasonably.