Transfer Case replacement

Kinda of a Noob question here...I'm going to the junk yard this weekend to get a np231 to replace the noisy leaking one in my '93 xj 4.0 manual. Is there any thing I need to know, like are t-cases interchangable between manuals and automatics, etc? I believe that anything after '91 is 23 spline so if I pull a post '91 will I be ok?

Thanks!!!!

I beleive post '91 pre 95 (because of the different TC output shafts)Good Luck

Thanks!