* Shop Manuals: A factory shop manual (often called a service manual) for your specific year and model is your best source. These manuals are incredibly detailed and usually include very clear vacuum diagrams. You can find these online through places like eBay, Amazon, or dedicated classic car parts websites. Look for ones specifically mentioning the 326 V8 engine.
* Online Forums: Join online forums dedicated to Pontiac Lemans or classic Pontiac cars. Members often have experience with these cars and may be able to provide a scan of a diagram, or point you toward a reliable source. Search for forums like the Pontiac Oakland Club International (POCI) forum.
* Restoration Parts Suppliers: Companies specializing in parts for classic Pontiacs may have access to the diagrams and could either provide one or direct you.
* Haynes or Chilton Manuals: While generally less detailed than factory manuals, these repair manuals sometimes include simplified vacuum diagrams. Check to see if one exists for your specific year and model. Be aware that the accuracy can be questionable compared to the factory manual.
Important Note: The vacuum routing can vary slightly depending on options (like air conditioning, power brakes, etc.) that were installed on your specific car. The diagram you find should match your vehicle's options as closely as possible for accuracy. If you can provide pictures of your engine bay, that might help others assist you in identifying the correct routing.
