Most likely he is. I basically compare what Oz would look like in the future to Jack Vessalius... because he certainly looks like him in a lot of ways.

If that were the case Oz would actually end up being 180cm which is about 5'11"

Though they don't actually say how much Oz weights anywhere...I'm not going to guess either... I think I only know Allen's actual weight xD.

Also LOL Light is surprisingly tall like Kaoru who is 5'10 and only 15/16 and still growing.