Pretty hard to tell from a video, but if I had to guess I would say it does sound a bit advanced.
Do you know if the high idle and cold start advance are turning off after it warms up a bit.
What I noticed with mine is that when it was a little retarded it sounded a little clunky like and old Mercedes 300 or something whereas when it is a little advanced it sounds a bit like a Powerstroke. That sounds Powerstroky to me, but I've made videos of my exhaust and they don't exactly sound the same in real life, similiar but not timing diagnostic similiar.
Nice looking truck though by the way.