Please see my other post regarding Cosmetic HG failure. The head now has some deterioration at all three upper sealing ring around the head domes and therefore would have to be resurfaced again. The factory service manual just says the service limit total between the decking of the block and head is .008". It was a stock motor that was rebuilt. Can anybody tell me how much material is typically removed when decking a block for the first time as well as heads. How do you guys determine if there is enough material left to resurface a head again? If you put in a properly torques spark plug into a chamber and measured from the top surface of the electrode to a straight edge held across the bore what should a factory head measure. How the heck can you determine the heads service limit without knowing a spec when new. Any advice?