What is the fuel mixture for McCulloch Mac Cat 38cc model 600038-21 chain saw?

I have model number 60003816 and I run 3oz of oil to 1 galion of gas. Works good but I'm not positive that's what is recommended.

The manual for that chainsaw requires a 20:1 mixture of non-McCulloch two-cycle oil. That is 6.4 oz. per gallon of unleaded gasoline regardless of what it says on the oil container.