It's no secret the oil formulation has changed due to EPA regs regarding zinc. Just as fuel no longer has lead, and we have to find ways of dealing with the long term results of low octane unleaded.

Fortunately modern chemistry has a loophole for us in ZDDP, but again not all formulas are made equal. I am betting on Brad Penn (which is green and really cool looking).

The cam in my '69 was bad when I got it, I just didn't know it. I compared photos I took in 2003 or 2004 with the cam as just pulled, the lobe wear did not change visibly, and the car ran no worse now than then. Actually for 3 bad lobes it ran quite well! And since this cam was flat long before ZDDP was removed from oil, there was another root cause. In this case, I believe it was lifters varnished in their bores from about 20 years of storage.