I'm not sure if it's legal or not, but Kenne Bell has the original GM build sheets for the motor reproduced for like $10. It looks shady to me, but I was impressed when I bought it.
I think American Musclecars Publications is the name of the publisher of the GN Facts and Figures books. I bought those as well and they're priceless. They have excellent exploded engine illustrations as well.
I know there is also a website somewhere that has these illustrations scanned, but I can't recall now. I think I found it when searching for LC2 on Google or something.