Aluminum Block Slant Six Racing MLS Head Gasket, 3.45 Bore 0.040 Thick,225,198,170,Slant 6Aluminum Block Slant 6 Head Gasket, Slant Six Multi Layer Steel 3. 45 Bore 0. 040 Thickness. This gasket was manufactured by using an original slant 6 aluminum block head gasket as a template. This is a copy of that gasket but produced in multi layer steel. This gasket is by far the best gasket we've found for the aluminum block. It seals well and can be used for performance builds that the stock gasket would not hold up to. If you are looking for the