np231 will it work for me (ASAP)

I have an 87 XJ (4.0) with the BA 10/5 and np231 (21 spline for that year). I need to replace the T-case and another member offered to sell me his np231 21 spline mated to an 89 AW4. Will his work for me? Are the input shafts the correct size? In otherwords, will it bolt right up? Thanks!

21 spline is 21 spline.

Get 'er done!

Yup. I'm running a 231 from an '89 AW4 behind an '87 AX5. 21 spline short is 21 spline short. You might have a small issue with one of the top studs being too close to get the nut on the end of it when you push the case onto the tranny. If so, slip it on partially and start the nut then push it flush and put the other 5 on, or you could pull the stud and use a bolt in it's place.
HTH,
Jeff

Thanks guys. Now to just nail down a price . . .

Even though spline count is the same, be sure to verify the length of the input shaft as they varied somewhat over the years.