Interesting how oils are so much better TODAY for our 50 YR OLD engines..that you have to ADD SOME ADDITIVE so that the flat tap cam will survive. Granted they've advanced oils...was it really toward 50 yr old flat tappet engines is the issue with that very general statement.
That was one big brain fart that danced itself right into comtridiction...like what happens when you type before thinking it through.
I'd take quotes and jump up n down on them but why bother, it speaks for itself.
If you need that last .0002 hp from oil... you more than likely aren't on this forum reading this discussion in the 1st place...that's out of this realm and even addressing it is so "cart in front of the horse" at this level its outlandish