I've run Valvoline Racing VR1 20W-50, 7K on this flat tappet side-oiler. One of the bullets on the back of the bottle says:
"Ashless anti-wear additives and
ZDDP provide ultimate wear protection"
It's API Service SM (exceeds API services SM/SL/CD).
http://www.valvoline.com/products/VR...otor%20Oil.pdf