as some of yall know, i overheated my 76 280 recently, and my machine shop tells me that the head is shot. now i'm shopping around for a new one, and i'm a little confused. my head is an N42. i've been led to believe that an N47 will fit my year and model too. what is the significance of these codes? what heads will fit my car? i'm also a little concerned about my block. the cylinders have some striation in them, and though my nail doesn't catch on them when i run my finger around a cylinder, it doesn't feel too smooth. i can't really afford to get them bored, but i don't want to get everything back together again to find out that the block needs service. should i be concerned about these striations, or are they typical?