Have a quick question for the experienced jeepers here.. I have an 88 YJ automatic with a NP 231 t case that's starting to make some noise. I found a tcase from a friend of a friend he "said" came out of a YJ.. I went today and bought it for 50 bucks. The tag was all covered in grim and dirt I scratch the surface enough with my finger nail to see it said 231 on it. Upon closer inspection at home it say 231HD on it. I was wondering if this is still a direct swap and if it was a better/worse tcase that what I have? Any help would be appreciated!