I had the same issue with orings I installed in June of 13. Went to international, got eight sets. Changed them all. Three months later, lost the ones on pass side rear injector. Lost another set on the same side. My truck would die too.
Im pulling injectors today, and I expect to find a bad pair on the pass side.
I ran two, thats right, two sets of orings from new in 00 until 09. 250k miles. Now Ive had oring failures left and right since then. I lost a set on a new injector two.months ago. I got injectors from Tim@PIS, which isnt his issue really, but the orings are garbage lately. I get alliants and whatever international gets. Im noticing allaint stuff saying "made in China" in the last two years.
The death of the 7.3 might be aftermarket support related. Cps are getting hard to come by in working fashion now too.