I was reading your other post, with the other vacum diagram, and by the calibration numbers, that one seems to be for a 79 460 on light duty trucks, yours is a 78 F150 right, with a swapped in 460?

If you can give me more information, I can try to get you the right vacum schematic, I have copies of some of the old Mitchell shop manuals, which is where I think these diagrams came from. . .