I love AC/DC. I have most of their vynil too. I used to work in a Record factory in '81. (It's a body shop now). 
I remember when that album came out. I was either a senior or my first year of college. 
I have it on CD.  It's a must have album. It's as important as Pink Floyd, The Wall.  Or any Led Zepplin album. 
I've got a crate of old records.  I don't play them anymore because I can't find a needle for my record player. I don't really want to anyway, I can't stand the static off those records either.  I'm CD spoiled. My son, who's 10, asked me what those things were. I told him old frizbees.