* Specific engine configuration: The 440 came in various configurations (e.g., different camshafts, carburetor types, compression ratios). A high-performance engine will have different timing requirements than a stock engine.
* Fuel type: The type of fuel used (leaded, unleaded, etc.) will affect ignition timing.
* Altitude: Higher altitudes require different timing.
* Engine condition: Worn components can affect optimal timing.
Where to find the information:
1. Original factory specifications: The best place to start is the owner's manual or a factory service manual specific to your 1970 Dodge Charger 440's engine code (found on a sticker under the hood or on a plate in the engine bay). This will provide the base timing specifications. These are usually expressed as degrees Before Top Dead Center (BTDC) at idle.
2. Tuning: Even with factory specs, fine-tuning is often necessary. A mechanic or experienced enthusiast might use a timing light and adjust the timing slightly to optimize performance and efficiency based on your specific engine's condition. This often involves checking for maximum vacuum at idle or using a dyno.
In short: You *cannot* get the correct timing without knowing your specific engine configuration and consulting the correct factory documentation. Attempting to guess the timing could damage your engine. Start with the factory specifications, and then consider professional tuning if needed.
