Jim, along with what Bill said you might want to consider an adjustable vacuum advance canister. Before you start changing the timing, disconnect and plug the vacuum advance supply hose and go for a drive. If the pinging is still there you'll want to adjust the mechanical advance (loosen clamp and rotate distributor) but if it's not there a canister that gives you less advance than your current one may be the answer.
Brad O. > I have been advised by multiple sources that my timing > is too far advanced, b/c I am getting a slight > knocking when my car is under load- > > Jim
