Vortec 7.4l fuel pressure

[CrazyW]

I have a 98 k2500 with a 454, 130,000 miles on it, and am having issues with random misfiring under a load. I have replaced the cap, rotor, plugs and wires, and the issue has come back after only a few hundred miles. I checked my fuel pressure, and it has a solid 60 psi at idle and with the key on/engine off, but when given some throttle, it drops to around 50 or lower, and doesn't seem to gain any psi as the throttle is held down. Is this an indication of a bad fuel pump or plugged fuel filter? I have both parts brand new, waiting to be installed if so, but don't want to put them on if I don't need to. Please help!

[carriedi]

does your check engine light come on?

you should drive this engine with a scanner on it and graph your o2 sensor and watch your fuel trims. This will tell you if it a fuel problem. If the fuel trims look normal and then the engine starts missing you should look at the ignition side