I'm looking at adding a limited slip on my 90' RC 4x4. It has a 9 1/4 with 3.55's right now. Since these gears have 170,000+ miles on them, I thought about swapping them with a newer set of gears. I have a ring/pinion from a 99' Ram. It is also for a 9 1/4 with a 3.55 ratio. Will these gears slip into the older axle housing, or did they make enough changes for them not to interchange?