Idle speed is normal.
The computer controls the timing. It will move it where it wants.
The computer controls timing, it will set it where it wants.
Timing and idle setting maybe computer controlled and not adjustable. If they are adjustable should be 825-850 RPM
It is best to start at 8 degrees at 600 rpm for auto and 6 degrees at 800 rpm for manual. The total timing should be around 33 degrees.
It's an adjustible timing gear that retards and advances cam timing based on engine load and RPM using oil pressure and a toothed wheel with a bigass spring in it.
SBC timing should be set at about 6-8 degrees advance with the vacuum disconnected at idle, about 600-800 rpm
There should be information regarding the timing degree on a decal locaded under the hood.
That truck does not have a timing belt. It has a timing chain that will last the life of the engine.
The timing on a 1989 Dodge truck should be set to 10* after unplugging the temperature sensor.
timing should be set with chip disabled(curb idle)
The timing for a 460 Ford engine is 14 degrees before top dead center. The engine should idle at about 600 rpm.
The computer should set the timing automatically by the sensors. If you change it, it must be done with a handheld computer.