[Flatrater]

You could still have a fuel pressure or volume problem! This engine has to have the right fuel pressure or it will not run right. All the furl pressure regulaotr does is relief pressure when it is too much but you could have too little fuel pressure. If I remember right the truck should have roughly 60 psi pressure.

Other things that could cause a hard strat off the top of my head
Crank and cam sensors
PCM
fuel filter