96 chevy1500 w/ 305 runs bad after 5 mins of driving. feels like if lack of power and low rpm's. press pedal and very slow pick up. when fuel pump went out and i replaced it is when i notice this problem start. so i did tune -up ,cap, rotor,wires and plugs( did not gap plugs don't know if this will affect it). it has a new fuel new exhuast and tranny.i even replaced batt. i have heard maybe distributor being bad or fuel filterand even pcm problems. i do notice my dash light flicker and my charging gauge move quickly back and forth. some mention to use Seafoam thought the intake but i don't know what i should try. as far a fuel filter i did on when i change the pump about 5months ago. so i think i will chache it again. if any can help me please let me know .