Talking about Mitsubishi EVO series engine, its predecessor should be the 4G63 VR4 type of engine, but for the VR4 model, their cylinder head gasket material originally is just using graphite, as the engine need to coupe with the more powerful turbo pressure demand, the EVO series had modified the gasket material to metal type.
The requirement for the cylinder head gasket not just stop at this point, after it become the metal material, user starting to demanding for the thickness of the gasket which it go to 1.5mm to 2.0mm range, that's not all, there are also user demanding for a more bigger diameter on the cylinder head gasket piston hole. The original size of the gasket diameter is about 86.2mm but due to oversize of the piston modification, gasket diameter of 87mm become their new request.