I bought one out of a late 90s Cherokee as well to put in my Duster when I put the factory efi back on my 5.9. Like you said, I’ll cut out the spare well (tires don’t fit in there anyway) and I might even have to raise the trunk floor a few inches so the tank don’t hang so low. That’s why I’m wanting to see pics of how @MoparDan440 did his. If I end up not being happy with the result, I’ll get a Mustang or Charger tank and cut a hole and install a pump in it.