Well they ain't worked for me. I tried a valve cover gasket and a thermostat housing gasket. They have two levels and I got the more expensive of each....the fiber reinforced. I made sure the valve cover rail was perfect and the housing and head were both flat. I followed their torque spec to the letter. Both leaked like a senior citizen with incontinence. I tried over torquing slightly and that helped, but they still leaked. Into the garbage they went. I put on a cork valve cover gasket and a blue FelPro thermostat gasket ans no leaks at all.
