The ISBN of Vacuum Diagrams is 0-00-225425-5.
The service manual for your car (including a Hayne's) will have the diagrams. The vacuum diagrams will vary greatly depending on what engine/carburetor the car has. In the related links section, there are links to the various vacuum diagrams for this vehicle.
VACUUM-diagram FORD 2.9 l V6
i need vacuum diagram for a carter abf competition 8867
Buy a repair manual like Chilton's they have wiring and vacuum diagrams.
need vacuum diagrams(engine)for 1978 cadillac deville
probably under the hood
You can find heater vacuum line diagrams for your Chevy van in most Chevrolet service manuals. The service manuals can be found at your local library.
Diagrams are usually located on a sticker under the hood. If not, get a motor manual with vacuum diagrams in it.
You can get diagrams at www.autozone.com; look for the emissions diagrams for your engine make and year.
Your best bet is to buy a Chilton's Repair Manual. It has all the vacuum diagrams you will need.
Haynes repair manuals have good vacuum diagrams