Your only option may be used. They've been discontinued for several years. The part number for the 87-90 a/c delete pulley is 53002904, but I can't find any online. If you have access to a local junkyard, you may have better luck finding the correct AC compressor bracket for yours.
They are available online, but they're expensive. The part number is
These both have the vertical bolt mounts, but I don't know what makes them different. They are listed as being for Wranglers, but the part numbers are the same as Cherokees.
You may get lucky here, if another member has one available. Try posting in the Wanted