Everyone is so ready to tell you to throw usable things away and spend your money. Not I.
SJ oil has a maximum of 1,000 parts per million ZDDP. Unless you're running serious valve springs it should be enough.
SM had the maximum ZDDP reduced to 800 ppm maximum. I'd use it in a stock type engine, although I wouldn't use it for breaking in a camshaft.
If you are indeed using a lot of spring on your engine I'd suggest not using either and using instead something like Joe Gibbs Driven or Amsoil or.......
You could also use it with an extra additive to supplement the anti-wear properties of the oil.
You could dilute the high ZDDP oil with one quart of the other stuff per oil change.
I wish that all you guys who "know" so much about this subject would spend a day looking through everything that is online from a reputable source, about the issue. There are other additives that are being used to replace the zddp, but nobody talks about them. There is the fact that detergents compete with the zddp for space on the sliding surfaces.
Motor oil is like religion. People can get quite het up about it, yet most are going by faith and not what they've seen with their own eyes.
I have to say the Amsoil seller who is a board member has always provided information that was technically correct and could be backed up by tests. Still, when he posts a reply, most of what he hears back is "Yes, but".
R.
