If that 78-84 version of Hercules shows up, I'm betting on him. His career really shifted gears at that time. He was in fights till the last round.
Weaver was an unbelievable physical specimen. One of the most durable guys ever and powerful. Foster could punch and Weaver could be hit. Foster was a little mechanical and I think Weaver weathers early storm and knocks him out.
I rooted for Weaver whenever he fought. At times it was frustrating watching him not let his hands go or fight with any purpose. After awhile he would get mad or whatever and destroy his opponent. Just thinking if he could have started fights faster he may have done even more.