Well I am still having issues with the hesitation/missing issue. Just to recap symptoms and repairs so far:
Hesitates under normal acceleration
Extremely light acceleration it is fine. I can accelerate as hard as I want to once she gets moving.
During idle, in park, engine begins to idle rough after about 15 minutes. Idle gets worse and worse until the truck cuts off and a plume of white smoke shoots from the throttle body.
Hesitates and backfires when heavy gas applied while in park. Truck will cut off when this happens.
things I have fixed:
plugs and wires, ran great for 2 months. then...
new fuel filter
replaced bad throttle body gasket
I feel like I have eliminated a spark issue. Fuel and air are about all that is left. Does it still sound like a fuel delivery issue? I haven't checked the fuel pressure. I don't have a gauge and I don't know how. Going to try that next. Any other suggestions would be great.
Thanks.