Weeds,
For at least some years that panel doors came from the factory on A-D Suburbans, the rear-door stops/limiters on the Suburban were different from the rear-door stops/limiters on the Panel Truck.
The Panel Truck limiters had a groove and two-locations to stop the sliding arm. This allowed (as you said) the Panel Truck doors to open/rotate far enough around for the truck to back up to a loading dock.
The
Suburban limiters/stops did not have a sliding arm (and the Suburban could not come as close to a loading dock). A few years ago, I think MotherTrucker posted information describing this difference.
If this information is correct for all years, it might support the possibility that your doors were Panel Truck doors added by the dealer or later.
Tim
