Ive seen a guy 230lbs bench 530, so whats so hard in believing 320lb Hulk Hogan benching 550?
Just using bodyweight/size as an indicator isn't much use. Also, a guy who weighs 230 pressing in the mid-500s is either heavily using and specifically trained, or he is using a blast shirt, single- or multi-ply.
Just because Hogan hovered in the early 300s bodyweight during his prime does NOT mean he was capable of moving 550 pounds off his chest. This is a HUGE weight and most usually very specific training is required to achieve such a feat.
It's like those who suggest Arnold
must have been able to press 500 or more because he had thick pecs and large biceps.

These types don't really understand strength, power and the other just-as-important factors that contribute to massive strength feats: neuromuscular efficiency, etc.