Good info Wayne. Having Comp Cams recommend and a engine builder that won't guarentee and engine without using Rotella T speaks volumes.
I have heard that STP has ZDDP and I have heard that it does not.
I do know that the GM EOS (extended
oil service) additive is loaded with it. Also, so is the Crane Cams break in lube and I have heard some recomendations on running it on a regular basis, not just at break in.
The magic number for
zinc seems to be > .11%. But, more is not always better, there are limits. Here are a couple of charts that I have found:
http://www.repairfaq.org/filipg/AUTO/F_oil_facts.html
http://www.micapeak.com/info/oiled.html
http://www.ford-trucks.com/article/i..._Negative.html
No guarentee the information in these links are correct!