Cometic Gasket Head Gasket 4.060in. Bore .040in. C9070-040 Provide maximum sealing performance for todays high output engines and require no sealants Ideal for aluminum heads to aluminum blocks and aluminum heads to cast iron blocks withstanding the shearing force created by the two materials. No need to re-torque, the embossing design of the MLS gasket promotes an even clamp load across the sealing surface allowing for measurable reduced bore distortion