I will be bench pressing 350 with a slight bounce by May as I attempt to qualify for the CAASA Nationals in Canada for strongman in the <170-lb class. I would be shocked if Arnold didn't have at least 100-lb on that, but who knows? People put a lot of emphasis on the strength of bodybuilders, when it is not what they are judged on. I read that Gunter bench pressed around 365-lb for 8-12 reps on the incline, which some people called light - and maybe that would be fair to call light for a man whose off-season weight was 345-lb. But again, Gunter was a bodybuilder. To be honest, I respect bodybuilders like Gunter, as well as Phil Heath, who train to...you know...build muscle.
I am intrigued that a man like Gunter had such amazing genetics for bodybuilding, but didn't seem to have nearly the genetics for strength, regardless of his massive size. But, again...he trained for mass, as bodybuilders should, so it's hard to know for sure.
I think in Lou's day, with less known about training, bodybuilders probably did train to get stronger, assuming there was a correlation between strength strength and muscle size. Of course there is a correlation, but hypertrophy-specific training something that became a thing after Arnold himself popularized bodybuilding. As I said, in the Ironage, less was known about training, and exactly what a person had to do to become a bodybuilder wasn't understood as it is today.
Lou was pretty strong though - he did compete in the World's Strongest Man competition, back in its first form, when it attempted to determine if powerlifters were stronger than bodybuilders or if bodybuilders were stronger than Olympic weightlifters.