Here is the story, got an extra head when i bought a 78 z ,supposed to be for Z, took to machine shop to go thru it and do valve job. They think it is a 80's model N47, any way to futher identify other than N47, have intension of putting it on my 77, cause the cam is trashed on it. It has no oiler tube, holes in the cam lobes, no place to plug up in the cam towers. am i screwing up by swaping it without knowing what it is, hell dont know anything else about the motor either????????