anybody done a 4.0 HO swap from ZJ/WJ

I've got a line on a 4.0 HO from a '99 WJ for cheap and am a bit concerned that the alternator and water pump mounts are radically different. I know this stuff all changed hard in 2000 and I am considering grabbing some of that, but I'm just looking for some comfort that the bolt holes are in the right places for my existing '91 junk to mount up.

I'm pretty sure it'll bolt to your tranny, but the harness won't even be a little bit compatible with your 91.