An unfinished cylinder head casting for producing a cylinder head for internal combustion engines powered with diesel fuel includes a sealing surface, intended for mounting in a finished state on a corresponding sealing surface of an engine block, and designed on a sealing surface section of the unfinished cylinder head casting. A thickness of the sealing surface section in a casting state exhibits a machining allowance in relation to its set thickness, obtained after a material-removing finishing of the sealing surface. The sealing surface includes a combustion chamber region, associated with a combustion chamber formed in the engine block. In the case of such a cylinder head, an optimum load-bearing capacity is achieved in a simple manner in that a combustion chamber region sealing surface section machining allowance amounts to a maximum of 15% of the machining allowance of the sealing surface section in the remaining region of the sealing surface.