I'm not sure what to call it but I get spewing from the head. Both areas that sandwich the gasket are smooth and I'm sure the head was torque properly.
Smooth is one thing, but are both surfaces absolutely flat?
Any distortion, subtle dips or high spots on the gasket surface, of either the cylinder or head are open invitations to let a head gasket leak or blow out; no matter what the gasket composition is.
Duct tape a sheet of 150 or 200 grit wet/ dry sand paper to a thick piece of glass and gently work the head then the cylinder over it using a figure 8 motion. Keep the sand paper wet with water (1 drop of dish soap to 1 gallon of water works good) to prevent it from loading up with metal.
About every 5 passes turn the cylinder or head 90 degrees so as to avoid favoring one particular area.
Do not take off too much material or you will increase the compression ratio even higher than it all ready is. The goal is to only true up the surfaces. When you first start out you will see where the sanding is only affecting the high spots. You will know when it is done when the gasket surface is evenly sanded all around. If you really want to see what is going on, evenly "paint" the surface with a permanent ink felt pen in between each 90 degree rotation. The ink will get removed only on the high spots first, then when it is getting removed evenly all around you are done.
Thoroughly wash all parts with HOT soapy water to remove all traces of metal dust before re-assembling.