i dont know if this is real, but i know one thing...
when ufc brazil hapenned, brazilian tvs did shows with the fighters, Tank being one of them. They showed him on a gym, doing barbell curls, and he was curling (dont quote me on that, i think it was more or less this...it was a long time ago) 180lbs or close to that for reps! with good form and it looked like he could do more...i remember after that appearance lots of people start to comment on that, even the guy who fought him that day (Pedro Rizzo if im not mistaken) did some interviews and commented on that
Not the biggest weight ever curled, but for someone who look like Tank its a big number (well, he does have a big structure)