The Heaviest handed Heavyweight (say that quickly three times ), is Frank Bruno, no one, not even George Foreman, had as heavier hands as him, in the last 20 years IMO.

Tyson, Lewis and I think Ruddock, are fighting it out for the most powerful punch, but that is different, as they got their power though timing and technique, whilst Bruno relied more on being heavy handed, and it showed, because his power never quite got him the success at the very top of the division.