Holyfield's chin was ATG level. However, regarding the Holyfield vs Foreman fight it has been written that Foreman realized too late in the bout that Holyfield could not take his body shots. If Foreman would have heavily targeted Holyfield's body from the opening bell, would it have potentially affected the fight in any meaningful way? (Either Holyfield was just too mobile no matter what, or a bruised (or broken) rib(s) could have made him a more stationary target)
The flip side to this is Foreman would have left his big round head open when going downstairs to the body. Holy was already landing some very dangerous and heavy combos even with the tight cross arm guard and puffed up Foreman's eyes. Part of Foreman's success also came from his thudding jab, but he himself admitted he was putting a little too much on his jabs and ironically pushed Holyfield out of range for the follow up combos. So I guess it boils down to if Foreman can manage to break down Holy's body before his eyes get swollen shut and if he can shorten up the jab a little more. If not it'll just end the same as before or Holy wins by TKO.