Mine had the 'rattle' too, but not annoying. While pulling a grade north of Flagstaff at 75, 7500 out back, my clutch started slipping, about 200 RPM above reality.
I put a new SBC Con O in and the rattle is gone, and the clutch is as smooth as you would ever expect it to be, and should be good to the HP level I expect to stay at (yea right). The clutch looked perfectly new when it came out, a near mirror image of the one that went in, excepting the friction material.
But, the flywheel had a definite ripple to it, and the wear pattern that was developing on the clutch and pressure plate was in the middle of the clutch face, not the outside edge, and no cupping was evident.
I bought the clutch without worrying about price when the dealer insisted that as the warranty says, on page 9, 'MANUAL TRANSMISSION CLUTCH PARTS ARE NOT COVERED AT ANY TIME'. I didn't want a replacement the same as what was in it, and I didn't want the amatuer hour tearing apart my truck at the dealer.
If this bit about the rattle is true, I'll be seeking some compensation from DC for their oversight.
Thanks for the clutch Fred, works great, I just need to repair the dent in my credit card now...
