Looking more closely, it looks like the cylinder may be salvageable. What you see in the picture appears to be aluminum build up on the cylinder wall, not wear. it might need a 99.75 overbore, but probably not all the way to 100.
This failure does mean I have to finish the tear down on this block, not just leave it as a shortty and swap pistons.
I have no justification for blaming injectors, but figure it does not make any sense to rebuild without checking them. 100K miles on a set of injectors probably is enough to justify a flow and pattern test. I am just as likely to replace or upgrade them though.
The more I look and research, the more convinced I am to use a gapless top ring set when I do rebuild. It should reduce blow by and equalize pressure and heat on the second ring land. if you notice in the piston failure picture, the piston failed at the top ring gap. It is highly likely that the failure was in ring land 2 and then it just progressed up and down until it blew the hole in the piston.
Not sure I mentioned it, but a section of one of the '04s piston's 2nd ring land fell out while the piston guys were inspecting them. I don't recall for sure, but believe that may have been in the gap area as well. Apparently failure in ring land 2 is the most common failure on these pistons/engines.
Back to the original topic of this thread. Not sure when, but I will definitely need a machine shop. Still looking for recommendations.