In 1974 Dodge was still building big trucks like semi tractors and 4-5 ton trucks. Some of the pickup style campers were getting pretty big as well. It would not be out of the realm of possibilities Dodge created a super heavy duty pickup to cart around those huge campers. It could also be possible Dodge joined with a camper manufacturer to build a special unit.

After all that, the 1 ton (5/8" wheel studs) brakes and suspension was pretty massive and could be hard to find in some locations. Gene