Ok, here are arguably the top two hardest punchers of all time, but they both lack a very good chin. So obviously this would be a very exciting fight. Cooney had IMO the hardest left hook of all time, and Shavers had IMO the hardest right of all time. Cooney stood at a towering 6'6, and Shavers stood at an average heavyweight height of 6'1.
Who wins this exciting, but more than likely short lived slugfest?
It depends on if you mean pre or post-Holmes Cooney. After Holmes, Cooney was left to rot in a mire of poor self-esteem. He never got his confidence back. However, even so, he gave the comebacking Foreman a pretty hard go before crumbling. I think the circumstances - having the entire nation rooting for him, and then betraying him and labeling him a bum - really sent him crashing harder than just losing ever would have.
In fact, come to think of it, an early shoot-out with Earnie Shavers either would have given Cooney the kind of stern test he would need later in his career, or crushed him early and have saved himself and the rest of us a lot of trouble.
Given the Holmes and Foreman fights, I think the pre-Holmes incarnation had enough stamina, skill, and heart to out-gut Shavers. I don't even really see it being a shoot-out. Cooney
could box if he needed to; just ask Larry Holmes! He would use his size and reach to wear Shavers down, and then come in (relatively) fresher and finish his man off in a short, closer of a shoot-out.
Cooney TKO8 Shavers
Unless, of course, Shavers lands the puncher's shot. Given his formidable power, it would be easier for him than most. Still, Cooney beats Shavers 8 times out of 10.