Here is an interesting interactive vacuum gauge link. Scroll to the bottom of the page and run through the various scenarios.. good stuff thumbs_up: http://www.secondchancegarage.com/public/186.cfm

One of the gauges I installed along with volts, oil press. and water temp. gauges in my '65 is a vacuum gage. In regard to tuning, a vacuum gage is essential.
http://i645.photobucket.com/albums/...nt%20Jan%202010/InteriorRepaint003-1.jpg

In the Stovebolt Gallery ~~ "The Orange Crate" 1965 C10 SWB Step Side Build Thread

Inspired to be different. Different in a way of my own, not in a way that others strive.