It's time to buy another 5 gallons of engine oil for my old Mopar LAs and RBs, and it would be nice to find something relatively economical. I have been using "Traveller" brand "fleet diesel oil" 15W-40 from Tractor Supply (due to its price; it has the lowest price I have found for such an oil), and which is advertised as being OK for older engines:
Traveller Premium All Fleet 15W-40 Diesel Engine Oil, 5 gal. at Tractor Supply Co.
However I doubt that the Traveller "diesel" oil contains any zinc, and I'm thinking maybe I should be using some other oil instead that would better lubricate my flat-tappet camshafts. I would appreciate any suggestions, while bearing in mind that I'm basically a cheapskate. Thanks.