249 vs 231 tcase question

Have 1996 XJ with NP231 J. I have a little play in frontend output yoke. I found a 1998 NP249 J tcase. The only diference I can see so far is the rearend ouput shafts are different. Now for my question can the rearend output shafts be swapped between the 231 and 249? Please don't laugh to hard I'm very sensitive.

Round metal tag on tcase says 249 J with 242 gear ratio. I believe it came out of 1998 grand cherokee.

No- although made by the same company-the internals are different.It has a lot of different parts due to the viscus coupling in the full time system.
Wayne

Thanks! Goes back to junk yard Friday. Luckily owner agreed to a refund when I bought it.:yelclap: