However, Edelbrock generally recommends using Autolite AR3924 or a similar equivalent (like the Champion equivalent) as a starting point. These are a common and readily available choice that often works well.
To determine the *best* spark plug for your specific setup, consider these factors and consult resources:
* Your Engine's Specifics: The exact displacement (289, 302, 351W, etc.) and compression ratio significantly influence the heat range needed. Higher compression and larger displacements often require a "colder" plug (lower heat range number).
* Ignition System: The type of ignition system (e.g., points, electronic ignition, HEI) affects plug selection. A more robust ignition system might allow for a slightly hotter plug.
* Fuel Type: Using higher octane fuel may influence plug choice.
* Edelbrock's Website and Documentation: Check Edelbrock's website or the instructions that came with your cylinder heads. They may have specific recommendations based on their testing.
* Spark Plug Manufacturers' Websites: Autolite, Champion, NGK, and Denso all have websites with cross-referencing tools and heat range guides. You can input your engine specs and find suitable plugs.
In short: Start with Autolite AR3924 as a reasonable starting point, but don't hesitate to consult the resources mentioned above to fine-tune your spark plug selection for optimal performance and longevity. You might even need to experiment with slightly hotter or colder plugs to find the ideal heat range for your setup.
