Cash for Clunkers did remove a LOT of these truck from off the roads, those sitting in the hedge rows and tree lines, back yards, etc. Also the price of scrap steel several years ago was much higher than it is now. I used to see a lot of older cars, trucks, combines and field implements (here in Kansas anyway) refrigerators, stoves and almost anything steel being hauled to the scrap steel yards in Wichita. Not so much now but still on occasion. All those factors put a limit on the supply of "buildible" trucks and the parts that can be supplied for such by visiting a "salvage yard" if there is such a thing anymore. Most yards in Wichita have nothing going back beyond mid to late 90s except a few skeletons and bones. Those that remain are more of an "automotive parts reclamation center" in that extent.
Thus, one of the few remaining areas to obtain parts leaves the inter-net which is nation and world wide in its content. Swap meets are also a possibility but even there the good parts are few and a lot of rusted out over priced scrap. Good quality GM original parts continue to be in demand and NOS continues to be found less and less with each passing year. If you want it and need it then your options are limited. Buy it and use it or do without.
Glad I had a love for these trucks before the days of BJ, Mecum, Russo & Steele auctions and the lot. Bought my rusted out POS long bed 4x4 for what it was and what it finally became after lot of effort, time, $$ and beer.
May not be up to BJ standards but I still love it as much today as I did years back and still turns heads and gets the question asked:
Hey Bud, that truck for sale? Answer: Nope, but thanks for asking.