I just ran across this thread, will post a link from the GT40s forum, where Webers seem to be the first choice whenever possible. First is a link to a YouTube video regarding tuning Weber carbs:
Weber Tuning Tutorial - On YouTube - GT40s.com
In addition, I ran across this CC article explaining the overall operation of Webers in general, posted by Tom Kirkham:
http://www.lainefamily.com/images/WeberTuningManual.pdf
They're tricky to sync, is what I've heard.
Cheers and good luck with your project!
Doug