But since you now know that oil needs zinc (zddp)for flat-tappet cams, especially during the initial break-in, keep in mind you can have too much in the oil too...so don't go overboard adding excess oil supplements to get the zinc levels up there. Too much zinc can be equally harmful.

Most decent speed shops will stock a zinc (ZDDP) additive that specifies how much should be mixed w/ what types/amount of oil....whether it is GM EOS or something similar.

I'd drain the oil, run a heavier wt diesel oil w/ the a ZDDP additive...makeing sure to prime it good and quickly before initial start up. Good luck!