Heavyweights keep getting bigger and bigger. Lewis was 6'5 and around 240-250 pounds, and he was taller than most of his opponents. He'd probably be considered about average size for a HW today.
How big do you think HWs will get in the future? Will there be a significant increase, or will it plateau?
When he was in his late 20s Lewis weighed in at a trim 225 pounds or so. In his mid 30s he was a softer 240. The best heavyweights won't likely get any bigger. Some heavyweights weigh a lot like Ortiz and Miller because they carry 20 to 40 pounds of fat they would be better off without. Wlad and his brother and AJ were true hard 245 pound boxers and I think that is as big as any good heavyweight champ will ever be.When boxers go beyond a certain size that extra size does them more harm than good. They lack speed and stamina and often don't take a punch that well. They don't punch harder because they are not as coordinated as a smaller heavy weight and lack hand speed and technique. Giant Fury doesn't punch that hard or take a punch that well. Remember what 185 pound Dempsey did to 250 pound Willard and what 198 pound Louis did to to 260 pound Carnera. I doubt we are in for a new era of 260 to 270 pound heavyweight champions. There have always been giant heavyweights and few of them ever make it to the top.