I picked up a '99 4x4 with a 5.2. It had been sitting a long time but fired up running rough. Replaced plugs, wires, cap, rotor, and had injectors cleaned. Truck runs much better but still a rough idle feels like a dead miss but runs well at higher rpm. Suggestions for troubleshooting ?

If you have access to a scanner watch for misfire.

Check for miss the old way, unplug plug wires one at a time.

Compression test

possible intake plenum gasket leak, look in intake for signs of oil

I've read about the plenum leak but don't understand that causing a dead miss. What about the idle air control?

Try some throttle body cleaner.

Bad gas? Battery low? Maybe pull the iac motor and clean everything up in there.

Can you smell gas under the hood? Bad injector seals will cause that symptom...