thanks for the input guys. well yesterday I loaded up the fam and we hit the local wrecking yard to check out a 231. after checking the tag, running through the gears and counting the spines on the input and output (my 11 yr old with nice young eyes actually did the counting), I pulled the trigger and paid $270 for a case w/manufacture date 10/99 out of a 2000 xj.
I'm going to take your advice and not do the SYE until a vibration says otherwise, if at all. thanks for the input!
regarding the 249, I am sure is a great case, I just would like plain old 2wd, 4hi and 4low.
the jeep has really become a part of the family!