Vacuum Guage Readings

Vacuum gauges were an option in the rally dashes in most early a bodies in the sixties. Then in the 70's and early 80's some cars were equipped with a light in the dash to remind you of fuel conservation.

I had a vacuum gauge in several cars and it is great to use for diagnosis and fuel economy purposes. Of course, common sense works for fuel economy, too, but a vacuum gauge is a great "trainer" for getting more MPG. Light throttle provides the highest vacuum readings, thus the best MPG. 2 inches of vacuum will show you that your foot is in the firewall...fun to watch.

A fluttering reading will tell you that you have a burnt valve. Many diagnostics with a vacuum gauge.

here is one website with info:
http://www.centuryperformance.com/vacuum.asp