* Engine modifications: Has the engine been modified? Modifications like different camshafts, carburetors, or heads will significantly affect the optimal timing.
* Distributor type: Different distributors have different mechanical advance curves.
* Engine condition: A worn engine may require slightly different timing than a well-maintained one.
* Fuel type: The octane rating of the fuel used also influences the ideal timing.
Therefore, you cannot find the "correct" timing without more information. The best approach is to:
1. Consult your owner's manual: This is the first place to look. It should give a base timing specification for your specific engine configuration. However, keep in mind that this is usually a starting point.
2. Check the distributor: The distributor often has markings that indicate the initial timing. This might provide a clue, but again, it's just a starting point.
3. Use a timing light: This is the only reliable way to determine and adjust your ignition timing accurately. You'll need to connect a timing light to your engine and then observe the timing marks on the harmonic balancer while the engine is running. You'll adjust the distributor until the timing is correct according to your manual or a reputable source that specifies the timing for your specific engine setup.
4. Find a shop manual: A factory shop manual for your specific year and model Mustang will give you the most detailed information and specifications, including base timing and mechanical advance curves.
In short, don't rely on a single number found online. Use the resources mentioned above to find the correct timing for *your* 1970 Mustang 302.
