Well, any way to make it flat is good. I sometimes used some sandpaper on a piece of glass for some of my bikes too (although with separate heads for each cylinder, which is a bit easier to do this way). But a milling machine will make it nice and parallel to the valve cover surface (while sanding it may not be too precise in this way). Never did it this way for an inline engine with a merged head, but it would probably be alright too.Oh, wow. I'm new to all this and haven't bought a new head gasket yet, so I had no idea there was an aluminum mesh in between. What's the best way to get the aluminum piece unstuck from the head?
Pikl, is milling it the only option? Could I stone it flat if it isn't too warped? I'm a machinist so I could just do it at work next week, but the quicker option is always preferable.