Where can you get a vacuum diagram for an 84 Z24 4x4 your Haynes manual is not correct?

The correct vacuum diagram should be on a decal under the hood. Also; some parts supply chains have an online service which provides certain vehicle repair information you might try(AZ?).

right now 9/17/09 they have a85 Nissan 720 service manual on eBay for 29.95 ,i paid 75.00 for mine thru Nissan dealer.