lol he was never 6’8, not at his peak, no today, not ever
I can't fathom Hulk being under 6'5" or 6'6". He probably wore a chunky heel that made him look 6'7", which allowed him to get away with saying 6'8".
Today, being over 65, and after years of neck and back surgeries, I could see him being 6'3" or something. I think he himself said that.
So if he shrunk to 6'3", what would his max height have been? I'd think easily 6'5". I'd be shocked if he was less than 6'5.5", which you can call 6'6", which makes his 6'8" claim less exaggerated.
He seemed pretty lanky to me, especially for a guy so muscular. That said, I was also basing Hulk's height somewhat on the 7'5" lie height claim for Andre the Giant, who was probably for sure a legit seven feet, but unlikely any taller.