[Spartan]

Think about how many trucks were built. Now think about each part that can be replaced. GM estimated how many parts to make based on how long they would support these trucks and how many were produced. So in essence NOS parts are common...but common is relative... and look out, not all NOS parts are NOS. Some parts sold as NOS were GM Replacement parts re-popped in the 1980's by GM. Some consider these to be NOS parts just depends on who's doing the selling I guess.

refurbishing an old part at more cost or less cost might be an option.

As stated this site is the best place to look for what you need. Become a member, pay for subscription and post a wtb add. OR wait until what you are looking for surfaces.

Just remember the hype over NOS might be a little inflated and leads to crooks trying to make a sucker out of you so do your homework/research.