I think I have clutch problems.

As an update to this, Carmax replaced the clutch under waranty and send the flywheel out to be resurfaced at a 3rd-party machine shop. I think the noise is still there, but it seems to be a lot quiter. People that ride with me say that it is not nearly as loud.

HOWEVER, now I noticed that if I try to disengage the clutch above 4,000 RPM, it won't disengage. Keep in mind, I don't have a habit of going this, but I have noticed it on one or two occasions. I've noticed that even if I rev the engine with the trans in neutral and the clutch pushed in, I can feel a decrease in pressure from the clutch pedal once the engine passes 4k. If I try shifting at the redline from 1st to second gear, the clutch pedal stays on the floor until the engine's revs drop.

I've tried the test to see if my clutch is slipping and it doesn't seem to be. The truck easily can squeal the tires in first gear, and if I put it in second at low speeds and rev the engine and let the clutch out I get a chirp from the tires, so it doesn't appear to be slipping at all.

Anyone have any idea what would cause this? Could this happen if the machine shop didn't step-cut the flywheel properly when they resurfaced it?