Found my dads original 1971 duster!

When you change the oil you need to use oil with zinc. I think the the brand is classic car or hot rod oil. I will look in the garage and let you know for sure.
Wow. Really? I’ll post a pic of the kind that the engine builder sold me. See if it’s proper. I’m sure it will say zinc on it, if it’s the right one then. Thanks!