Dont use Zinc additive. If you want to run high ZDDP use this on the track, M1 0w50:
https://www.summitracing.com/parts/m...UaAiCcEALw_wcB
It's M1, which is what we're supposed to run in ZL1s. And it has very high Zinc over 1850 PPM I think. 15w50 has 1300 PPM.