Holley Power Valve Experimentation

What I did was take the PV right out, and installed a plug . then put my vacuum gauge on the windshield , plumbed to the intake. Then road tested it to see what the engine wanted. Pretty quick I figured out that she wanted something around 10/11
Then the testing began, but first I had to learn how to use that tool, cuz it was spitting out numbers that had nothing to do with the codes on the valves.
Since I was pretty sure my gauge was accurate; I calibrated all my valves according to it. then I just selected what I thought was about right, and screwed it in, and bingo. Beautiful, smooth roll-ons.
My valves were a mix of new and used, and it seemed like the used ones were closer to correct than were the new ones.