the results
Well, based on a sample size of 14 as of today, there is a pretty even split between Mexico and St. Louis made trucks. Either 1) the 'bad' casting factory in Brazil supplied both plants (due to the location of other plants this seems unlikely unless it was an 'overflow plant' that directed production based on need), 2) more then one casting factory had the problem or 3) there is more to the problem then we know.
Considering Cummins reputation, it seems unlikely to me that the so called Brazil factory simply misread the specs. As I understand it, they were not producing these under a license from Cummins, they were producing them FOR Cummins. In which case Cummins would have had production engineers all over the place. I guess anything is possible though.
I've poked around a little trying to find out what kind of supply chain Cummins/ Dodge had for these engines but haven't had much luck. Would probably have to find an insider at Cummins to confirm if its #1 or #2 above.
In the meantime, I don't think I'm going to lose any sleep over it.
-Vic