All oils have ZDDP in them. For all but the most high performance motors its a complete non-issue. Plus at ZDDP levels over 2000ppm the ZDDP starts eating metal.
There is a letter you can google from a GM lubrication engineer regarding the ZDDP issue, and it quite a good read. Its in the December 2007(!) issue of the GM Tech and Service bulletins or
HERE You can use it if you like. The big points are:
All motor oils are backwards compatible so current SJ oil will perform the same/better as older API specs.
There IS a specific lifter wear test in the API specs that must be passed... so again, all oil TODAY is as good as or better than old API specs.
Flat tappet cams are made today... they are called 'inverted bucket' design... so its not like modern cars have all switched to roller rockers.
ZDDP has been LOWERED because it will damage catalytic converters (a cam is cheap compared to a new catalytic converter) BUT while ZDDP HAS BEEN REDUCED other additives have been added to provide the same protection.. just with a different additive.
You do not need a special break in oil. You can use it, but unless you have a very high performance motor it does nothing so make the break in 'easier'. Just look at modern engines. They are simply started up and driven away from mile #1. Nothing special is done to them at all.
