I was doing some digging around on the internet this evening and found out that the Valvoline straight SAE 30wt VR1 oil has more zinc in it than the VR1 10W-30 oil does.
If you only drive your truck in warm weather, the SAE 30wt oil may be a better option if you have a flat tappet cam and want maximum zinc content.
Here's the data:
https://sharena21.springcm.com/Publi...2-ac162d889bd1