Doing a head swap over the winter. I would like to go to a thinner gasket than the stock GM MLS but the Cometics seem to be problematic for a lot of guys. If you were successful in using Cometics, how did you prepare the block? I have had some recommendations to use a honing stone to smooth out the block, but this may end up violating the flatness requirement. This swap will be done with the engine in the car so machining the block is out of the question.