For Cherokee's, up until 1995, they used 260's for non-ABS and 297's for ABS equipped. 1995 and up got the larger 297 ujoints with or without ABS.
This does not apply to YJ's though. My friend has a 1990 YJ without abs and it uses 297's.
So yours uses 297's. Which can be, as mentioned, upgraded to 760's. Same size, just stronger.
Brute Force sucks, ya.
The AutoZone computers will be wrong. They sell 260's for non abs for all years and 297's for abs all years. So be careful if you do want to get Brute Force ujoints and intend on using AutoZone's computer.
OR simply just bring in the shaft with you to ensure you get the right size ujoint as well, if you'd like to.