I've got a '92 Champion built for the Detroit Airport. It's a Chevy 6500 chassis with a tbi 427T bolted to an Allison 545.
27' bumper to bumper
19'6" from the back of the drivers seat to the back door
7'6" wide inside.
I picked it up for $800 with minor engine problems, fixed the engine, gutted the inside, and am currently moving all the battery cables and battery box. Next step is to remove all the rust scale from the gas tank and line it then start on some of the rusted sheet metal on the exterior followed by paint, roof sealer, new window seals and exterior lighting before moving back to the inside.