So called clunkers
This is the same crap that resulted in the hot rod magazine crusher camaro project from years ago, except they figured out a way to make you, me and everyone that pays taxes finance this one instead of trading emissions credit to oil refining companies for a large number of junk cars. Hot rod magazine paid $800 for an immaculate LA based 6 cylinder 1968 camaro when the last one went down, from the line a Chevron if I recall correctly. I think it had a 572 in it the last time it made the rounds, one I'd be pround to have in my garage but I don't make enough money to buy it even if it was for sale.
We live in the UP of Michigan and believe you me with the iron moss it's pretty easy to find enough '84+ vehicles to make scrap out of, and a couple of our rangers would be among them if we were in the market for a new car or truck. Hell we have one going for scrap after taking a few more parts next week!
My understanding is that it's really just glass beads, and that the motors shut down RIGHT NOW. I would think this is primarily the result of crankshaft and rod main seziure, but I could be mistaken. I would question the urban myth about heads being wrecked as well, but you can pretty much put the valve train in a heap, because it's going to get abrasive crap before the engine stops too.
IMHO, if there are ways to get heads off some of these motors that are desirable it's worth a try. There is so much SBF stuff out there I can't imagine not being able to use the stuff if it makes any sense... But it's kind of like having a third click on the fire selector of your AR-15 that isn't necessarily marked - you better be damn careful.