I think you talking about the old diesel oil Rottila (thats spelled wrong) and ZDDP additive. Use the search function on Moparts or slant six.org there was some real good discussion on .org.
Hope this helps.
Frank
Rottella has the proper Zinc/heavy metal additives and is safe for your initial fire-up. EOS is no longer carried by GM. They now use a cam reak-in lube they sell by the bottle. The reason they gave me is that people were using EOS on the newer GM cars/engines and it was creating a warrenty problem in that the EOS somehow was messing up the emissions.