New Rear Gears

What does your cam require? What transmission are you using (and stall if auto)? What do you plan on doing with the car? 3.55 is a damn go balance between take off and cruising! Also know that you can now get 3.73 gear ratio for the 8.75 rear (which I'm assuming you have/are using), which also a great balance between 3.55 and 3.91. Why mopar didn't offer it from the factory I don't know.

One other thing, have you thought of using an o/d transmission?