Hey Sam, I don't know anything about the Brad Penn stuff Pete recommended. I don't know the rating. All I know is I would stick to the rating I mentioned before. Even if that stuff has more zinc, but is racing oil, I wouldn't use it in our street/strip cars. Besides the zinc, we need the full additive package to combat combustion gases and by-products in the crankcase. Racing oil is ok if we want to change our oil every 100mi. I like my rings to stay loose in their lands and not have my oil pan rot out from corrosive contaminates.
Verne