The RV Consumer Group recommends Wheel Base/Overall Length of AT LEAST 53%, NOT Less Than 53%.
GAWR-F = Max Axle Load for Front Axle
GAWR-R = Max Axle Load for Rear Axle
GVWR = Gross Vehicle Weight Rating. The most a loaded coach can weigh
CGWR = Highest Weight Rating for Coach PLUS towed vehicle or trailer
A Truck Scale will give you Front and Rear Axle weights as well as a Total Weight. On a New or Empty Coach, GVWR - Scale Weight is what you can carry - People, Supplies, Food, Water, and so on.
Compare Front and Rear Axle weights with GAWR-F and GAWR-R. Be sure the Front has adequate loading (1/3+ of Front Weight) and the Rear isn't at/over/close to GAWR-R.
While you're looking at the placards in the Door Jamb, the max pressure for Front Tires is 65-psi, and that's based on full GAWR-F. You can safely go to 65 and you'll see better ride and tracking. With actual weights, you can likely go lower, using a Load/Pressure Chart from MichelinRV.
EDIT: 4600-lbs and 65-PSI are for 2007 and older E350/450's. Newer ones take higher since GAWR-F is 5000-lbs. 70-PSI if I remember correctly, but still not 80-PSI. A simple 5-PSI change will improve ride and tracking.