I meant year.
I have a remanufactured 318 bought from a chrysler dealership in 1987 (so it has flat tappets) that had about 10k miles put on it from 1987 to 1998 and has been in storage until the last couple years when I changed the oil (10w30 non synthetic, probably penzoil or quaker state) but car only driven a few dozen miles since then.
I don't recall doing anything special during break-in other than maybe changing the oil after the first 100 miles.
I'm curious what zinc levels that would have been available in ordinary off the shelf oil back in the late 80's and early 90's because that's what the engine used during it's early life. But now that I'm back at the car, I want to get my head around what oil I need to be looking for since so much has changed in the past 25 years. So zinc levels are my focus on this.
Viscosity is secondary, I didn't think oils with large viscosity ranges were durable, but maybe that's different now. This car will never be winter driven so I don't need low temperature oil. But the car will sit for long extended periods of time for the forseeable future, I'd rather not have to change it just because of the passage of time vs the miles put on it, but maybe that's not realistic (you tell me).