Can anybody help decipher the codes on the tags screwed onto the 231j transfer cases? Primarily the assembly #'s. It seems to be a 8 digit number. Does this indicate how many splines the inputs are or the year it was made?
What I have definitely learned from nearly 2 hours of internet searching is that my 99 definitely has a 23 spline input. The case i picked up tonight complete with SYE and may have been as old as from a 89 XJ. I didn't count the splines off this t-case yet as its now resting in my shop a few miles away, that will have to wait until tomorrow i suppose. But was curious if anybody had quick knowledge of this.

 

The 89 will be a 21 spline input.

 

ok , so yep the transfer case is from an 89 with only 21 splines. So in trying to make this work, what are my reasonable options?
Is swapping the input shafts a viable option?

Or should I hit the pick and pull, grab another t-case and swap in the SYE to that one?

OR crack mine open, see what is messed up with the front output, try and repair it then swap in the SYE from the older 231? What would you do?