Fuel pump Advice, please! Which is best: Bosch, Walbro or ?

[swathdiver]

I'm confused. The OE Delphi fuel pump description for my truck at RA states "w/o flex-fuel."

That's right, because yours is not FlexFuel capable. A FlexFuel capable truck has larger injectors and a higher capacity fuel pump to feed those bigger injectors. If you put a FlexFuel pump in your truck, it should work just fine. Just need to pick the right one that can handle 450+ horses. Anyone ever hear otherwise?