Most of the NASCAR guys run Joe Gibbs racing oil. There's another brand they also use, but I can't remember the name of the maker/blender. He's out of Denver, I think . . (Edit: Just read hammertime's full post. That's the guy)
High RPM engines with flat tappet cams generally use high Zinc content oils, and it really looks like black chunks of mud in the oil pans. We generally use the GM "Startup" oil X 2 in our first warmup. That and the engine assembly Lube makes the oil look like swamp water when you drain it . .
That's also why the T/F guy's oil looks so bad . . They have a ton of that additive in the oil on every pass, or so I've been told by a couple of the crew chiefs . . Now that's on a "good" pass . .
Gotta say, I've never seen anything worn out by overlubrication . . .