The street versions of the Boss 302 and DZ302, were quite comparable in performance. Some points were better on the Boss, while the Z/28 had theirs also. Very closely matched. The T/A cars were just the opposite. The Boss had the horsepower advantage, while the Z had better weight bias. What made the difference, race to race: the drivers. Sometimes Parnelli had the advantage, sometimes Donohue. The rest is history...