Which oil?

The magic number you're after is roughly 1400ppm of zinc and phosphorous. More phosphorous is usually better and is actually the additive that helps shear and pressure resistance of oil on flat tappets and pistons. You need zinc for longivity.

VR1 is good oil in track cars. I like something with a low level of detergent, for the street, to keep it cleaner on full change intervals. Track cars usually see more cylinder wash, inherently see more frequent oil changes and less buildup between rebuilds than a street engine.

I run Penn Grade 1 for a street solid tappet.