* Year of the vehicle: The specifications changed over the years the 318 was produced.
* Engine modifications: Any modifications (camshaft, carburetor, etc.) will significantly alter the ideal timing.
* Fuel type: The type of fuel used can influence the optimal timing.
To find the correct timing setting, you MUST consult your vehicle's owner's manual or a reputable repair manual specific to your Charger's year and engine. These manuals will provide the correct base timing specification, and may also include instructions on adjusting the timing based on vacuum advance.
Trying to guess the timing can cause serious engine damage. Improper timing can lead to poor performance, reduced fuel economy, overheating, and even catastrophic engine failure. Always consult the correct service manual for your specific vehicle.