[Healeys] Oil Additive Question

[Mark and Kathy]

I don't recall the well known  STP additive being mentioned much on the list
when talking about oils and additives.

 It says on the bottle  and paraphrase, " the most anti wear additive of any
leading brand"   and in very teeny letters it says  "ZDDP anti wear additive"

Hmmmmm, can it be as simple as adding a bottle of STP to my  20w50
Castrol to help break in my newly rebuilt engine.

Any suggestions hear?

Not much info on their web sight unfortunately.

I have 2 cases of the SM  Castrol 20w 50 and would like to use it some how.


Mark