Sifting through information stretching back only a year the best info I have found puts Mac McClung's vertical leap at 48 1/2 inches. I would add that seems fairly accurate but that number is still climbing. I noticed in the video twitter above his body is transforming into a sleeker look.
Which is another oddity about McClung. In some ways his body type and size is somewhat comparable to ex Indiana star Damon Bailey. I was very intrigued by Bailey when he was just coming out of high school where he led his small town school to a championship which I remember watching on ESPN at the time. Yes they televised the game because of Bailey. Bailey made headlines ( and the legend started) a couple of years prior to that when Knight said he was better than anyone on his current team in the best seller book by John Feinstein "A Season On The Brink." I still have the SI basketball preview article featuring Damon which is where I found out he sported a 39 inch vertical.
Bailey was sturdily built at 6'3" but wasn't long or lithe like so many of other up and coming players. When I first saw McClung I thought he was built more like a football running back rather than a high flying back court basketball player. McClung is built like a lot of White high school basketball players who never advance much further. A bit stocky with non Orangutan like limbs. And for such a prodigious dunker even McClung's hand size isn't anything resembling the big paws and long fingers one usually sees in basketball players. Larry Bird had big ole paws. Dr. J and Michael Jordan had the longest fingers I have ever seen. John Stockton even had big hands for a player his size.
So in a word McClung is a true outlier in many ways. But it is also important to remember that like sprinting the "experts" hype up the idea that blacks have better leaping ability that Whites. Problem with that is the one event that most accurately measures leaping ability is the high jump and blacks do not dominate that event in track and field. In fact White women have been the dominating force in the high jump over the past decades. But you won't hear a peep about that from the black athletic supremacy crowd who carefully tailor their message to form fit their propaganda.