Power Valve #'s

The only time I've seen power valves marked as per your example is if they were original equipment at one time. It sounds as though the selection of valves that you have may be from a bunch of different used OE Holley or Motorcraft carbs. I would suggest buying the correct one for your application rather than playing "hit or miss" with a selection of used valves, as the used ones may be blown from a backfire.

Here's link to Holley's power valve selection guide: http://www.holley.com/data/TechService/Technical/power_valves.pdf

Good luck! :)