There's a great many guys deserving of mention before Ingo. He has a KO of Patterson who was decimated twice by Liston, and an impressive quickie KO over Machen who proved to be durable and elusive over his career. Both men were sub 200, not the be all and end all but still. It's just not near enough. Mike Tyson hasn't even been mentioned yet and his right hand would absolutely swamp Ingo's. Incredibly fast, immensely powerful, effectively delivered as a hook, cross, overhand or uppercut and then we have his famous right hand to the body, right uppercut to the head combo. The more i think about it the higher I'd have the Tyson right hand. He's top 3 for me i think.
Marciano's right hand...the "Suzie Q"...Widely considered by boxing historians as one of the "most devastating single weapons in boxing history!" Burt Sugar went so far as to call Rocky's right hand..."the most dangerous right hand ever brought into the prize ring!" Watch the Walcott KO in 1952...'nuff said...