A '92 Ford 460 has a fuel injection system rather then a carburetor(since '88). So with that said, I would do the easy things - and first of all replace the fuel filter which is relatively small in relation to the engine. I would then check the electric fuel pump output pressure and then the fuel injectors. Occasionally the throttle position sensor will cause a surge problem, but usually it will cause erratic throttle operation and major acceleration stumble. Then, there are those O2 sensors in the exhaust - and a '92 - about that age for replacement. They feedback to the computer, to determine the fuel mixture. There is also a water temp sensor, but it's something that seldom causes any pain. You also could dry or Teflon lube the linkage (forget about WD40 - it is a water displacer first with a small amount of lube qualities). Also, it probably has an E4OD transmission which may be 'hunting' while in overdrive. This is the last item to check if it seems to shift up and down correctly.
Let us know what you find!!