You can find a free Ford F1 50 vacuum diagram at most Ford dealerships. Many auto-parts stores will have the vacuum diagram.
The vacuum line diagram is not available for free. It will have to come from the Ford service book, or from a Ford dealer.
You can get a 1999 Ford Taurus 3.0 liter engine vacuum diagram from Ford service manuals. The service manuals will be available, for free, at most local libraries.
autozone.com has free online manuals
go to autozone.com, they have free pics
Look for some F150 forums for the wiring diagram. Don't hold your breath waiting to find a free shop manual.
Google search - 351M vacuum diagram
Your best bet is to buy a Chilton's Repair Manual. It has alot of pictures and diagrams.
Which vacuum diagram The Underhood for the engine or the vacuum for the interior /AC system?
Check out the Google Images and search for '93 Ford F150 heater hose'. you should find it there.
Go to the dealer. The service department will provide you with the diagram showing all vacuum lines free of charge
www . motorcraft service . com ( no spaces ) When you get to the home page - click on Owner Guides Select your year and Ford model to view the Owner Guide ( which includes the fuse diagram )
There should be a vacuum hose diagram on the front of the driver side strut tower.