High-zinc oil or ZDDP oil additives?

Joe Gibbs Driven HR5 is going in my 67 Barracuda. I've used Napa and Valvoline with zink additive the last 3 years. But I never let the oils in any of my vehicles get black. When it starts to turn dark that's when I change it. I keep clean oil. I'm gonna try the JG stuff to see how it does.