Man, I read these all the time, and... I feel for y'all... I've yet to experience this, but that hasn't stopped me from forming an opinion on the subject.
I've spared y'all until now, I guess. But, here goes:
Thermal expansion and uneven distribution of heat. It's my contention that issues arise not over miles or age, but cycles instead. It's a thermal wall and is best explained by saying a hot pressurized liquid being pressed into a cold stationary liquid creates a momentary boom, akin to thunder. That collision creates a shock that, each time it happens, weakens the union. The weakest link is where the container meets the manifold and at the line where hot meets cold.
I know there are people smarter than me here, let there be no challenge about that, and I know mishi has spent a good pile of cash researching and developing a fix... I think that body mounts is misplacing effort, though. It's just my opinion, and has no value outside of that.
In my humblest opinion, I'd like to see owners do one of two things... One contradicts other concerns (such as economy and wet stacking), and is allowing the truck to warm up slowly, as in stationary, before operation. When the thermostat opens in a short period as opposed to slowly over minutes, and pumps a large volume through the radiator suddenly, you'll get that thunder that wreaks havoc on radiators.
The other, also in my humblest opinion and interjection, is an old fashioned hot rodder trick from way back in my past: before installing thermostats, drill three tiny and opposing holes in the blades.. 12, 4, and 8 o'clock... No more than a 16'th... This allows fluid to pump through the blades even while they're closed, which introduces heat to the radiator slower, makes warm ups last longer, but won't have affect on overall operating temperature (the exchange surface, volume of coolant, and flow of both air and fluids dictate cooling efficiency, not when the events happen).....
That is my speel... Maybe there is something to it, and maybe there isn't. I didnt come by this originally, exactly, but instead by applying data collected from aircraft cooling exchanges... Google 'football radiator' and read.. when you find it, you'll likely have an 'a-ha' moment, too.
Disregard googling...
linky linky