I'm not celebrating yet, but it looks as if the lift pump cured the problem. It definitely drives a lot livelier than it did before. Spools up faster and accelerates harder. I tried twice yesterday and once today to get it to screw up, and it hasn't yet. Hopefully it stays that way.
The lift pump install was pretty simple, just took a while, about 6 hours total. The only thing not included in the kit is chafe protection for the hoses. I had a little bit of large wire loom in the garage, but need to pick up some more. My only complaint (and not really one) would be that you can't verify if the pump is actually running. I'm going to have somebody push the over-ride button with the truck off and see if I can hear / feel it running. It's that quiet.