I love my 99-XJ, but the only thing I wish they would have not changed are the tail lights.
I love the look of the older style that had the more square look rather than the more feminine looking rounded look they went to.

I would love to do a swap if possible and was wondering if anyone has done it without much trouble.

I guess if it would take too much fab I would shy away from the idea but if it was a simple bolt on tailgate and lights I would do it.

 

The bodys are different so the tailgates do not line up or the tail lights, I was looking into putting the newer style in my 89 and found that out... lol

 

now if you swap the rear hatch out, then they should bolt up, i believe they have the same bolt pattern (please dont quote me on that). but the newer hatches are made out of steel, and the old ones out of fiberglass, so keep your steel one.

 

fiberglass has external hinges too.

 

Regardless if the bolt pattern is the same, the hatches have different body lines and wouldn't match up as previously stated.

Just looking at the two different styles one should be able to determine that the two aren't interchangeable.