Neither of these guys were ever hurt. It's probably about equal but if I have to pick...McCall. He faced more, bigger, big-hitters without being fazed.
Toss up but McCall probably had a better defence which sometimes enabled him to take the full steam off a punch. I doubt McCall is/was as physically strong as Chuvalo though.
I saw the stoppage of the Chuvalo vs Foreman fight. It's crazy, he didn't look anywhere near being hurt, didn't even move much and Foreman was landing flush punch after flush punch. But it was still a good stoppage though.
Also i saw HL of the Frazier fight and it looked to me like he got stopped because he got thumbed in the eye.
The youtube Video of Chuvalo vs Fraizer has this description. "In a brutal display of power, Joe Frazier fractures George Chuvalo's orbit (the bone under George's eye is damaged) so badly that Chuvalo needs reconstructive surgery to correct the injury as his eye partially drops into the fault line fracture. A career ending injury for mere mortals, Chuvalo continues his amazing career post surgery to cement his legend" :think
WOW amazing!! they just dont make em like that anymore. :good Ive never read up on the fight ive just seen the HL footage and i assumed Chuvalo just got thumbed in the eye, but damn" fractured his orbit bone under his eye " Tough SOB.