i have both heads and they are both stamped n47. Mn47 is slang for the maxima one to z folks, and zn47 is slang for the z one for maxima folks. Look at the chamber on the bottom mating surface, if its shaped like a heart its the mn47. if its round, its the zn47. Mn47 on flat tops na l28 will get you about 10:1 comp. Just have the big 280 valves installed and power up!