The 6.0 started off on a bad foot which affected its reputation for the long run. Perhaps didn't do enough testing with it
It was not a testing issue. The engine that IH had developed was as solid as any before it..... the FORD BEANCOUNTERS got a hold of it, and cheeped out on some of the components..... The beancounter goal was to ge it past the 100k mile warrenty, if the component lasted 100,001 miles they were happy.... since Ford did not have to pay for the replacement.....