Oil Additive

no, you need ZDDP for the initial break-in. once the cam establishes its wear pattern, zinc is not so much an issue.
cheers

No disrespect,but that is a great way to wipe out a cam lobe. It is absolutely important to keep oil with ZDP in your flat-tappet cam motor after break in.

You can either use racing oils with ZDP (Lucas,Quaker State,Red Line,Valvoline,Royal Purple,etc) or use your favorite oil with (no ZDP content) and add a bottle of
break in addative (Lucas,Red-Line,Comp Cam,etc) at each oil change.

I use Comp Cams addative.