leaf spring swap Q

before we start, yes i searched.
i heard that you can swap in dodge durago leaf spring to give a bit of lift. my question is can anyone confirm this? also what year would i need to pull them off of? thanks for the help,
Tony

PS: any major modifcations need to be done or is this a bolt in swap?

Obviously you didn't really search. This question has been asked and answered many times already.

You can use any leaf springs that are the same width as XJ springs. Springs from a spring-under vehicle (S-10 or Dakota leaf packs seem to be the most commonly used) will give the most lift. See Timmay's excellent write-up: http://www.naxja.org/forum/showthread.php?t=50083.

and understand that they are not swapping per se.
you use the main leaf from your ex jay and cut the helpers to size from the new packs. the main leaf is the one that connects on both sides, the helpers give it the bend. just make sure they line up with the centering holes.