Welcome Jon!!
I have a 2017 25' Thor Freedom Elite on the Ford E350 chassis. Experienced the same handling problems. Posted on my handle Roadking. I logged 1.5 million miles driving for business over a 40yr career. No heavies, just cars and light trucks.
I made one more upgrade not posted yet. I had the rear leaf spring shackles replaced with a product from Surlastic what a difference!! Before installation every bump was a mini earthquake. Wheel alignment made a big difference too
__________________
|