Ignition timing on 81 cutlass v6 3.8?

i had an problem for a while far as engine bogging down under acceleration sometimes ping i know its not the transmission cuz it has been doing it for a year now also i changed fuel filter and rebuilt carb and theres no cat on exhaust system i checked ignition timing upon checking the igition timing was at 10 to 12 degrees btdc and the spec is 15 degrees would this setting be whats giving me this problem?