Truck Repair: 1996 8.3 cummings, glow plugs, electric heater

Question
I have recently purchased a truck with an 8.3 in it. On the intake manifold it says not to use either to start. Dose it have some sort of glow plugs? How do they activate, and at what temperature?
                                           thanks, Leon

Answer
If it has a "helper" to start it will be an electric heater grid made in the intake manifold.Or an older version with a spark plug looking thing that screws in the intake.They are worked off intake temp.They are automatically activated by the intake temp sensor.