I hadn't heard of that Champion shop that Ron mentioned, in the Chicago area. My guess is Henderson's the best known, followed by maybe Brazel and EricsRV in a close tie...? All the names have come up, with Henderson most of the time, and I've had a lot of personal responses from Henderson about questions. Wouldn't hesitate to deal with any of them.
I haven't dug through the whole thread recently, so... What's the Loaded Weight Distribution on this Coach? Ford wants a third (why they call it 32% beats me) of loaded weight as minimum loading on the front axle. I'm thinking that if this unit has a little LESS than that, it could be OK without the toad and the extra lateral pressure the toad provides is enough to make it goofy.
On Tire Pressures, you really want the PSI a Load/Pressure Chart tells you based on what the front singles and rear duals (different ratings single and dual) are carrying on a truck scale, coach loaded for travel.
Many like higher pressures than that. Many inflate to sidewall max which is 80PSI for Load Range E.
More pressure than indicated by the Chart, or Chart + 5 if you insist, does the following:
1. Harshens the Ride (harder tire)
2. Compromises Braking (smaller contact patch)
3. Reduces Steering Axle Tracking (smaller patch means less surface pointing the coach the way you want it to go).
On an RV, I'm not sure more pressure in the rear will do much beyond making it ride harder. But more in front than it calls for WILL contribute to wandering.