Over the Counter Zinc Additive

Check out Schneider Cams Formula 2. I used it in my solid lifter race engine for many years. 1/2 bottle at each oil change. Worked great, ran the same cam/lifters for 3 seasons of 7500+ RPM with no wear. Also, I've had several local engine builders (Southeast Virginia) tell me not to use Valvoline VR1 unless I also use an additive.