I'll let someone smarter help answer, Savvy Aviator, here's link:
https://www.youtube.com/watch?v=eNuCcflYTbE
My IA goes with IRAN. It'll discover corrosion just like an overhaul which is the big deal. When I started slinging oil, IRAN was what was done. Plus, I got the idea some parts might have to be replaced with an overhaul..."and good luck finding those, especially for the rear prop" was the quote. Not only cheaper but faster. And local prop guys covered over, short staffed with big backlog. Anything to speed it up helps.