That is almost exactly what I did. This picture shows the line that comes out of the manifold and runs to the HydraVac. It also splits at the firewall and a branch runs to the wiper motor. I disconnected that large line from the manifold and tied in my vacuum gauge at that point. I did not plug that line since it was disconnected and I didn't know where it could be tied into the system at that it would cause a problem. Should I have plugged the line that supplies vacuum to the HydraVac and the wipers?

http://i1259.photobucket.com/albums/ii549/Parksman/Intake%20Vacuum_zpsykhi34oj.jpg

I don't know if that is the correct setup to even supply vacuum to the the HydraVac and wipers? I've ordered the electric wipers from Newport so that will be eliminated from the system next week.

Thanks for your help and advice.

1956 Chevrolet 4400
1955 Chris Craft Sportsman
1953 Chevy 4400 (patiently waiting its turn)
1950 Farmall Cub (my great-granddad's tractor)
1948 John Deere M (wife's great-granddad's tractor)