Mine were warped by .003", and on top of that one of the problems with the original '01 gaskets were that they corroded into the head causing groves where the metal part of the gasket folds over. There was a ring corroded around every cylinder and on the edges. Because of this they had to shave them .006" to get them flat. Make sure you take out your injectors and glow plugs first. When I did mine I took the heads out with the valvetrain, injectors, and glow plugs still inside. I removed all that on the bench. I put one of the old head bolts in on each corner from the underside so that the glow plugs and injectors wouldn't get damaged. A couple pieces of 2x4 would do the trick too. In fact you could screw them to your bench and then use some long lags to hold the head to the bench so you can work on it easier. Just don't torque it down. You may as well install ARP head studs while you've got it apart. I got mine for $580 shipped. If one of the vendors on here won't give you a comparable deal, just PM me and I'll get the contact info. I'll see if I can dig up the part numbers of the "type c" head gaskets. The third version that GM put out. The dealers I talked to had no idea what was what when it came to the gaskets and wanted to sell me the wrong ones. I had to go to one dealer an hour away to get one, and another an hour in the other direction to get the other one.
