Here are the best places to look:
* Your Owner's Manual: If you still have the original owner's manual, it's the best place to start. It should have a diagram, though it might be simplified.
* Haynes or Chilton Repair Manual: These manuals are inexpensive and widely available (often found at auto parts stores or online). They usually have detailed vacuum diagrams specific to the engine type. You MUST specify the engine size (e.g., 305 cubic inch small-block, 350 cubic inch small-block, 4.3L V6, 6.2L diesel, etc.) when ordering.
* Online Repair Manuals: Sites like ChiltonOnline.com or others offering online access to repair manuals can provide diagrams. Again, knowing your engine is crucial.
* Chevrolet Parts Websites: Some websites that sell Chevy parts might have diagrams accessible, possibly within parts breakdowns for your specific engine. You'll likely need your VIN (Vehicle Identification Number) to be certain you're getting the right parts and diagram.
* Online Forums: Search forums dedicated to classic Chevy trucks (e.g., forums on sites like ChevyTalk or others). Someone with the same truck and engine might have a diagram or be able to point you to one. Be sure to include your engine details in your search.
Crucially: Before attempting any vacuum hose repairs, *carefully label* each hose before disconnecting it to avoid confusion during reassembly. A misconnected vacuum hose can cause significant problems with your engine's performance. Take photos as you disconnect the lines.
