You know that sometimes people say life sucks. However, a little vacuum in your life can help your diagnose what ails your jeep or provide confirmation that all is well.
The vacuum gauge can tell you much more then a simple compression check.
See How to Master the Vacuum Gauge
You may not have a port on an early manifold. Army Motors told the troops to drill a hole for the vacuum port. 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.
If you would like to find out more about the WW2 jeep, especially the early history then check out, Jeep – Its development and procurement under the Quartermaster Corps, 1940-1942, for more information. It was written in 1943 when the information was hot off the press. It isn’t a perfect history. Is history on a given subject every perfect? Lots of footnotes to have you dig further, should you want too!