In my old version of my L30/M20 article I attempted to collate and correlate the available axle information of the time. The footnotes in it come generally from the Chevrolet P&A 30, but we have never been able to verify the background of those note by anything else. There does appear to be some truth to them, but based on more recent CRG database checks the P&A30 notes don't appear to be 100% accurate. Which is, in part, why I pulled the axle stuff out of the CRG article.
I call the old article old because it is old. I note in the CRG article that the CRG article supercedes the old one, and I do this because I want you to read the new one, not the old one.
I pulled the axle info out of the newer version maintained here at CRG because we've done so much new axle work since then that it wasn't worth trying to keep it separately current in this article. That doesn't help the everyday reader, I'm afraid, as we haven't published all the axle stuff yet, but it may come out this year.
I haven't looked to see if Alan has updated CBTN recently, but his previous axle info was fairly weak (as was the info in my older article), and unless he has found the original axle plant records, I look for the eventual CRG info to be more accurate with regard to axle codes for Camaro.