Never blew one up, but I have broken a roller clutch on the starting line in a 904. And I've seen the results of numerous roller clutch failures in Torqueflites and other brands.

Not trying to spread fear or scare anyone. Just trying to tell people it happens, as proven by all the sad pictures floating around, and it's not necessary or unavoidable. Use the right parts, maintain it, drive it right and put a shield on it. And stop thinking people are full of $#!+ because you've been doing it your way for a few years and nothing bad has happened yet.