Where do you find a vacuum line diagram for a 1973 GM 350 engine?

You can find a vacuum line diagram for a 1973 GM 350 engine in the vehicle's service manual, which often includes detailed schematics and diagrams. Additionally, online resources such as automotive forums, classic car websites, or sites like eBay and Amazon may have reproduction manuals or diagrams available for purchase. You can also check with classic car restoration shops or local auto parts stores that specialize in vintage vehicles.