Well, I emailed this fellow and asked what oil he used in this little engine, and here is his reply to me.
Good morning Johnny
Thank you for the kind compliments on my little Chevy engine. The oil I am using right now is Castrol Syntec 5W30. This oil seems to work good. Haven't torn it down to see about wear, but is has been run a lot, and hasn't come apart yet, and the cam and lifters seem to be standing up well. The valves require very little adjustment now.
Thank you again for the inquiry, Johnny.
Take care and Have a Happy Holiday.
Jim Moyer