96 cherokee t-case question

What would make a np-231 out of a 96 cherokee with the 4.0 any diffrent than the rest?

My buddy has broken his t-case in his 96 cherokee and everyone i have talked to has told me that you would need one from this same year is this correct?

I would think 92 or later should work. The spline count on the earlier auto was 21 instead of 23.

96 was a change over year. That is why alot of books say 96 only. 92 & up should work, set them side by side & compare. JIM.