[amac209]

a fuel pressure check would be a good place to start sometimes pumps will put out pressure but not enough volume so when fuel demand is high the pressure drops off and your truck starts bucking. a check of all the critical sensors is a good idea, if you have access to a decent scan tool this can be done fairly quickly, do a sweep test on the tps(throttle position sensor). but i'm almost certain you have a fuel problem, check the regulator for any leaks. if you can a good test involves installing a pressure gage and taping it to the windshield and going for a drive. pressure should increase when rpms do. also inspect the wires at the fuel pump, look for any signs of corrosion make sure the ground is clean and solid any extra resistance will limit the pumps performance.
good luck