Thanks gswgci. I had an alignment on the toad about a month ago and it seems to drive without darting so I think that can be ruled out. I set the Blue Ox up myself but it seems to be set up right. The tow bar is level and attaches to solid tabs on the Jeep's Rockhard steel bumper.
I was thinking of the shocks but was wondering if weighing the coach on all four corners and ensuring accurate/correct tire pressure might be first on the list. (I've been reading of several other Monacos having quite a bit of difference in the rear passenger's side being much heavier.) I'm not sure if it needs to be re-aligned given the only change was the tires.
If it helps diagnose it, the coach seemed to track ruts more than it used to also. I noticed that more on road construction where they had those blasted concrete barriers to keep it exciting during lane re-routes.
I will definitely pick a calm day and take her out without the Jeep as you suggest.
2008 Monaco Knight SKQ named Mona