Chevrolet Repair: 1987 gmc 454 dually stumbling upon acceleration, throttle position sensor, fuel pressure regulator

Question
I have a 1987 GMC dually two wheel drive with the 7.4 tbi engine, runs fine but stumbles upon acceleration, you can feather the gas pedal and seems to accelerate fine. Could it be fuel filter?  

Answer
Hello Brian,
Yes, could be the fuel filter.
I would want to test the pressure. There should be 13 PSI when running, at the throttle body.

Other possible problems are
Fuel pressure regulator.
Fuel pump.
Hole in fuel line connection inside tank.
Throttle position sensor.

Or an ignition problem.

If it eventually has plenty of power, after feathering the pedal, then I would lean toward the throttle position sensor.
Van