The 1976-1977 Chevy Blazer and GMC Sierra "Chalet" Conversions were completed by Chinook in Washington and sold
from Chevy/GMC Dealerships.
Neat concept that quietly went away after about 2000 units produced. The reality is that these trucks were overloaded with the loaded fiberglass shell on their back and as such did not drive all that great or safe. Over the years the shells have also been mounted on modified Suburbans and several to trailer chassis's.
Given the propensity for rust on these early Blazer/Sierra's you see many enthusiasts of these campers today remove the shell from the 1976-1977 Blazer/Sierra Chassis and mount the shell on a newer 1989-1991 Blazer chassis. Nice easy bolt on that immediately gets you Fuel Ijection, Overdrive Transmission and a little heavier suspension.
As you can see below there "Was" consideration to building a Suburban Chalet as this was shown in a GM brochure. Notice this was to be built on the 3/4 ton 2500 Suburban. This would have been a great Chalet had they proceeded with this concept.
The best modification that can be made that makes the "Chalet" quite off-road capable is to install 1 ton 8 lug Chevrolet 4WD pickup axles front and rear along with the appropriate suspension springs and shock absorber's. With this mod the truck will drive, ride and perform so much better.
I have owned 5-6 different "Chalet's" over the years. Kinda fun and quirky camper that gets lots of look IF you have a nice one!