Zinc oil supplement

No.
I’m taking the advice of a trusted engine builder and machinist that makes his entire living from high performance engines. I wouldn’t just abandon his opinions for some random guy in a forum.
yeah and i would as well if my engine was built buy a trusted engine builder.. they know the clearances they are the guys providng some kind of warrnanty why wouldn't ya

but my point is if you have a high zddp oil already adding more makes little sense
and it is easier just to buy a high zddp oil in the first place to avoid polluting the manufactueres good work...

basically avoid the 1 bottle good 2 bottles better 3 bottles etc situation you can have too much of a good thing.. you need the correct amount.

however i'm not going to ignore the advice of the builder.... i would want some piece of mind that if it all goes wrong I as owner am above criticism.

Dave