Murphy,
First, when posting questions about your RV, you should give as many details about it as possible. I did check your profile and see you have a 2012 Winnebago, which means it is on the Ford chassis, which is notorious for poor handling.
Size of tires is not the issue, chassis instability is!
The suggestions to check front-end alignment and weight, you will probably benefit from anti=sway bars up front and rear stabilizers. I do not know of the shops in Minnesota, so a posting getting recommendations for a shop in your area would help. You can also check the FMCA website and list of authorized suspension centers nearby.
Happy Trails! ;)