Some guys I used to race with, took a rolled E350 Diesel ambulance, and swapped on a 15 passenger body, to use as a race trailer and crew hauling rig. They raced out of it for years. Anyhow, the dad told me it took he and the boys a weekend to swap van bodies. Might have been an exaggeration, but as I look under mine, there doesn't seem to be but one big 'ole electrical plug, the steering column, and 10 or so 5/8" body-to-chassis bolts. Then there's the lift you'd need...