What are the factory timing specs for 454 engine?

There's no single "factory timing spec" for a 454 engine. The specifications varied significantly depending on the year of manufacture, the specific application (truck, car, marine), and even the specific model within a given year. Chevrolet produced 454s for many years, and each iteration had its own unique characteristics.

To find the correct timing spec for *your* 454, you need to identify:

* Year: The model year of the vehicle or engine.

* Make and Model: The specific make and model of the vehicle (e.g., 1970 Chevrolet Chevelle SS 454). This helps pinpoint the engine variant.

* Engine Code: If you can locate the engine code (often stamped on the engine block), this provides the most accurate identification of the engine's specifications.

Once you have this information, you can:

* Consult a factory service manual: This is the best source. A service manual specific to your vehicle's year and model will list the correct ignition timing specifications.

* Use an online resource: Some websites offer engine specifications databases, but always cross-reference this information with a reputable service manual.

Without the specifics of your 454 engine, any timing specification I give you would be unreliable and potentially damaging to your engine. Always consult your vehicle's service manual for accurate information.