Army Jill pauses by the 42 Ford GPW
The vacuum gage can tell you much more then a simple compression check.
See How to Master the Vacuum Gage
You may not have a port on an early manifold. Army Motors told the troops to drill a hole or the vacuum part. And I reckon to tap it for a plug as well. As an alternative you could fashion a spacer with a vacuum port for those jeeps that don’t have a port…and when you don’t want to drill a port.
