man, i can't tell for sure, i've never tried to put a tj bumper on a yj. obviously there has to be a difference. but anything can be done, but it just boils down to how much can you fabricate. yj bumpers are real straight forward, 4 holes to line up, thats alll, but i've seen nice yj bumpers. you can't find one you like?
i'd ask cherokee, since he's done a lot with putting his yj body on a tj frame. he'll have some input.