And somebody mentioned F450, a pickup chassis. A few Class C's are on F-Series but I'm sure the unit in question is on E-Series, a "van nose."
Check and make sure the Wheelbase-to-Length ratio is 55-60%. Too short (50-52%) the rear overhang will make it want to sway and wander. Front Axle weight should be at least 33% of loaded weight, or 75% of its rating. Too short and the Rear Axle could even be overloaded, but I doubt that in 26-ft on E450.
Include a Truck Stop on your Test Drive and Weigh it on their CAT scale. Make sure the Front Tires are equally inflated, around 55-60-psi, and the four rears are equally inflated, probably around 70-psi.
Satisfy yourself with Weight Distribution because you really can't change it much. Tire pressure is really important and free. You can do Alignment and add things like Sway and Track bars later.
