That is Good that someone in the business has a whole kit that is probably compatible to the original parts. I also have original parts in the barn to grab when needed, is great. I also bought 2 new kits from GM twenty years ago and put them in the garage for the day that I would have to use them.
The day hasn't come yet but I am kind of surprised that GM does not have in inventory. But then again if you do not move the product or repair the trucks, you do not continue to stock on the shelf. Tells you for one that the original hoses and springs, caps were made to last.