Is the cam timing the problem, or something else?

I have tried adjusting the initial advance as far as 22*, there is no detonation that I can hear, and the MSD distributor is one that came with the car, so I have no idea what may have been done to it by the po. The oe distributor came with the engine and I have run it as high as 22* initial advance as well. The only thing noticeable at that point is the starter drag.