Interchangeable gears in 8 1/4?

Here's the question:

I'm planning on putting 3.55s in my Dart, and a friend is replacing the 3.55s in his dads 2001 Dak V6 with 3.90s. I know there are differences in the carriers & spline, but are the gear sets themselves the same between the pre-96 and post-96 8.25" rear ends?