When I got my '89 suburban it had most, if not all, options on it. The question is that it has a pair of fiberglass running boards that start at the front of the front wheel well and continue to the rear of the rear wheel well they also have an aluminium step from front door hinge to end of rear door. Each is a one piece unit approximately 24 inches shy of the length of the suburban.

I've looked at all the RPOs for that era that I could find and can't seem to find any information about them and the dealership that sold the rig originally has changed hands. I'd like to know if it was an exterior package for the Silverado option, a dealer installed aftermarket item or what.

I've taken them off, partly because the wheels look small ,width wise and out of place (15x10 235/75 R15) and when last painted the shop didn't remove them and the paint is coming off around the wells. Even though they are in what I feel to be remarkable shape; I want to refurbish and build new supports for them.
I'd like to find a visually correct, functional wheel and tire combination to use with them but for now I'd appreciate any info regarding them.