Shuttering/lerching while driving

I have a 1987 Chevy S-10 Tahoe pickup with the 2.8L TBI Engine. It has 219,680 miles on it and no leaks that I can find. I recently had problems with it not cranking when the motor was hot(ie running errands, going to see family, anytime it has been driven for more than 10 min). Upon troubleshooting and replacing the fuel filter, vaccum hose to the canister, oil pressure relays, and both oil pressure switches I have gotten that taken care of. Now when I am driving down the road it will do like a shutter or a lerch like it is not getting enough fuel to the engine. Usually it does this when traveling at highway speeds of between 60 to 75 mph. It does it at speeds below 50 mph but not as often. I am not to sure that the pump is not going out. But I do hear the pump come on when I turn the key on and hear it run for about 2 to 5 sec. After I cut the truck off. But I am also not sure that there might not be a clog in the exhaust also. I had a 85 Dodge Ram 50 sport that did about the same thing when the catalytic converter went out. Checked to make sure that there was not back flow on the exhaust pipe. Do not feel any backflow at the pipe. Any idea's what it could be or what else would need checked?