Isx surging or rough idle

[Chamberpains]

Sounds like an injector. But also check the metering and timing actuators. Physically pull them off and pull them apart and check them. Rawze has instructions on here for checking them.

I don't know about using sea-foam on your engine. Thats a $20000 gamble on if your gonna burn something or break something with pre-ignition. Plus maybe dislodging a possible obstruction or gum and then ramming it thru the fuel system and ultimately in to the injectors.
If you suspect an obstruction its always better to search for it thru process of elimination then clean it out off of the truck, than to try and dissolve it and force the gunk thru.