Amsoil has the ZROD oil, that has the zinc in it already, plus it is Amsoil, so IMO it is one of the best oils you can buy.
I am sure its expensive.
In my stock 69 383 I have been using STP 10w-30 , and adding one of the blue STP oil treatment bottles (it has ZINC added )in, or dumping a bottle of Lucas TB zinc plus, in.
As long as you add the zinc, if running flat tappet cam, then you can use what ever brand you like .
The Lucas TB zinc plus, it is $12 a bottle, the STP is $3-$4.
I am sure there are a lot of opinions on this, I look forward to reading peoples thoughts.