block swapping question

[amcinstaller]

ok, so i read through the block faq and even all the links in it, except for the naxja one that wouldnt work for me, might be dead. i even read all the suggestions that it gave me for my title. anways, i think it will, but i need to know if a 91 wrangler block will fit in a 91 XJ, cause i have a chance at a runner for my project. is there a place maybe that says what casting numbers came in which models? that would be a really fast way to check that kinda stuff

[Carl]

Differences iirc is water pump, fan, belt routing, oil filter adapter not used on yj. The block itself is the same.