I never knew of an issue with the 4wds but it was a known issue on certain years of the 2wd trucks. I've replaced the fronts with Moog Cargo Coils on the 2wds to eliminate the lean before.
If it wasnt noticeable til 130K (unless that was when you 1st got it) there is a good chance it is just from normal wear and tear, when you are teh only person in the truck, you are on that side. The gas tank is also on that side. After several years it would not be surprising for a truck to lean that way.
When I was an alignment guy, often (not always) all I had to do on vehicles with torsion bars (especially trucks/ and at that, especially Chevy S10s and S10 Blazers) was to crank the torsion bar on the low side to match the height of the high side, and the alignment would mysteriously and magically come back to "dead nuts". Alot of times no need to mess with shims or cams to bring them back into alignment. Often the driver side would be 1-1/2" lower at the center of the front fenderwell vs the passenger side, and if I had to then make further adjustment, it was usually on vehicles that had previously been aligned, while the truck had the lean. Before I sent my Durango in for alignment I made sure that my front end was level and cranked up to where it needed to be. (I no longer have alignment machine access, wish I did)

also if there is a problem in one corner, it will be also noticeable in the diagonal opposite corner.