Engine oil

Did a search and came up blank..I would have though this had been beaten to death.

I just finished a resto mag that stated that our new engine oil is very bad for our classic cars because there isn't enough lube for the tappets.

The suggest a good quality , non synthetic, with a 1/3 of a can of Chevy oil additive.

Does anyone have any opinions..assume 5 to 8K Kilometers a year.

Thanks
Ian.