Pillsbury was a wonderfully gifted player who took up the game relatively late in life (at about the age of 16, which is ancient for a future world-class player), died when he was only 33, and was dealing with syphilis during his entire career as an international-caliber player, yet probably only Lasker had a better claim as the top chess player in the world during that period.
I, too, would be curious if anyone has a higher rating than an 8k time. I was fairly close (roughly 2200 and 23:30), and a combination of something like 2345 and 23:45 sounds very doable to me, but they're both pretty time-consuming pastimes if you're really serious about developing your potential. I chose running over chess. Now, thirty-five years after my last rated game (and more than twenty-five years after my fastest running), I've returned to chess as an enthusiastic spectator, and even played in a blitz tournament a few weeks ago, but I don't think that I want to get super-serious about either chess or running ever again. They're both insanely addicting, at least to me.