* Chevrolet Repair Manual (1970 Impala): This is the most reliable source. A factory service manual will have a detailed diagram, often color-coded, showing the correct firing order and wire routing. You can often find these manuals online through retailers like eBay, Amazon, or specialized auto parts websites that sell repair manuals.
* Online Repair Manuals: Websites like Haynes.com or ChiltonDIY.com often have downloadable repair manuals, which include wiring diagrams, for many classic car models. Make sure you specify the engine size (e.g., 350 cubic inch, 454 cubic inch) as the wiring will differ.
* Online Forums: Searching on forums dedicated to classic Chevrolets (e.g., Impala forums, Team Chevelle forums) might turn up someone who has scanned or photographed the relevant section of a repair manual. Be aware that this information is user-submitted and may not be entirely accurate.
* Your Local Auto Parts Store: Some auto parts stores may have access to repair manuals or databases that include wiring diagrams. It's worth asking.
Important Note: When searching online, always specify "1970 Chevrolet Impala" *and* the engine size (e.g., "1970 Chevrolet Impala 350 small block spark plug wiring"). This will significantly improve your search results. The firing order and wiring will vary depending on the engine.
