Regarding the "warranty" vs "over the counter block" difference, it is my understanding that because all the extra motors Chrysler built were shipped to their depots, any kind of part you ordered "over the counter", short block's included, would be considered just that, an over the counter item and it would come from the depot to the dealership for you to pick up.
If it was a "warranty' block it is no different, would come from the same depot, assuming the dealer was warrantying a motor that needed replacing and the dealer would install it under warranty.
After a number of years or a period of time, like all parts at a Chrysler depot if they were deemed a 'slow moving part' the parts specifier would arrange for them to be scrapped, to make room on the shelves for more current parts. They would then take the parts off the books and out of the system, NS-1.
I know of a bus load, sitting since the late 70's, of old 60's 383's, 361's, 273's...any 340 and 440's are long gone.
Everything was purchased from the Chrysler depot in Mississauga, Canada when Chrysler scrapped them, or was supposed to do so..
They are all short blocks, had the blue riveted blue tag and accompanying paperwork.