So, you might ask, "What is a 1976 GMC motorhome anyway?" Good question. Most motorhomes of that period were based on a standard truck or a van chassis. Motor in front, rear-drive. The living area made out of aluminum trailer material attached to a frame of wooden 2x2s, perched on top of the high truck frame. The construction technique did not hold up over time, they have a real tendency to leak, and it is nearly impossible to repair any damage in that flimsy structure. Very few 70's vintage motorhomes survive.
The GMC is very different.
The drivetrain of is based on the front-wheel drive system that GM developed at that time, and it is basically the same as used in the Oldsmobile Toronado, Buick Riviera, and Cadillac Eldorado.
The use of front wheel drive made it possible to build a motorhome that is not nearly as high as those that have a driveshaft running underneath. The floor is just much lower, requiring only a single step to enter. The skin of the GMC is done in aluminum, built much like an aircraft with aluminum skin riveted to aluminum ribs. The end caps front and rear are large fiberglass moldings.
I lusted for a GMC when they were new, but they were out of my price range, so I settled for one of the 2x2-aluminum things. Maybe they would get cheaper as they got older.
Well they did get cheaper, and they got older.
I finally bought my coach in 2004, and it was cheap. It was also a basket case.
I called my basket case 'SWAN2B', since the ugly duckling could become a beautiful swan, given enough time and money.
I did a complete mechanical rebuild. Engine, transmission, cooling system, brakes, suspension, wheels, and tires. A lot more than I had budgeted, to be sure.
Then came the exterior. I thought I would get the mechanicals done (focus first on Safety and Reliability), then I would work on the interior (plumbing, electrical, carpet, upholstery, etc.), and finally, go after the exterior (body repairs, new lights, windows, windshield, wipers, paint job). My spouse had other priorities. She just could not stand the way it looked, so the exterior had to be done before the interior. The majority of the exterior work is done, the paint job is cool, and all the leaks have been repaired (well, maybe most). The interior has a new water heater, lights, carpet, and some new upholstery. Still more to do.
I have never really attempted a major rebuild like this has turned out to be, but I am happy with the results thus far.