Just a couple of questions for @wcsmith: Have you been replacing the canister fuel filter (not referring to the sock on the pump itself)? A partially clogged filter can cause tremendous back pressure at the fuel pump which can cause early pump failure.
Have you been using original equipment pumps (AC Delco)? It’s not a part you want to economize on considering the difficulty replacing it.
A word on GM fuel pump failures: My last 8 cars have been GM pump in tank cars and only one has had one fail and that was at 267,000 miles. I guess every ones experience is different.