Vacuum lines and schematics

Does anyone know where I can find the specs for vacuum lines for an 75 F250 Heavy Duty truck with a 390 moter, 4 bbl carb, and a granny 4 speed. So far all the information I and my husband have been able to find is for a lighter truck. The truck was made in 1975 and sold origanally in 1976. My husband has bought the truck about mid -1980. He has not had trouble smogging until this year. Since there does not seem to be any specs, no one will touch it as far a reconnecting vacuum lines. Any help would be appreciated. Its a great truck if a little cranky, my opinion as a female. This is a Calif vehicle made and sold in Calif

You might be able to find the info here. It has a Forum as well so you can ask the question there:)
http://www.ford-trucks.com/