Chris,
I use Valvoline Racing oil, 10W-30. Unlike most over-the-counter motor oils, this oil has some zinc content. I also add a bottle of the ZDDPlus zinc additive. If the bottle of oil has the little gear symbol that says "for gasoline engines only", it does not contain any zinc. According to the guys at my auto parts store who have done some research into this zinc issue, the Valvoline Racing oil has the highest zinc content of all the over-the-counter oils. Even so, it's still not as high as the oils designed for the older engines. That's why I also add the bottle of ZDDPlus.
John