Safety

[HBadger]

Is it true that Class B rigs are built to greater safety standards than Class C?

[Winterbagoal]

Probably.
Vans are built to higher safety standards from the factory. FMVSS and NHTSA.
Cab chassis are probably the same, althought they aren't a complete vehicle.
Once the upfitters get them, who knows?

[Knittler]

I would say that without a doubt that a class B using an OEM body is way safer and better tested than any class B+/C on the same chassis.