The 45 ft buses of today are not your father's Oldsmobile,it takes very little to overload the front axle, that is why you see the 365/ 22.5 tires on the front axles now. Conversions are heavy Newell and Prevost are 55,000 GVW lbs now, my Country Coach was 52,000 lbs GVW. They are not using the old reliable straight axle any longer to carry the weight on conversion, they use the independent suspension and it offsets the 130# psi in the tires ,you can check the Prevost VIP shells for weight and the conversion VIP shell is rated higher than the passengers' model. Good thing about a DYI conversion you don't have to use all the Granite counter tops, stone floors and 4 slide outs folks want today