Resurfacing Cylinder Heads Blocks? Mistakes to Avoid
Jun 01, 2007· But the recommended surface finish for the same type of head gasket in an engine with an aluminum head on a cast iron block is smoother, typically 20 to 50 microinches Ra. On late model engines with multilayer steel (MLS) head gaskets, the OEM surface finish recommendations tend to be even smoother, say 20 to 30 microinches Ra or even 7 to 15 Ra.