So I just caught the end of L.A. Confidential on cable, and it's been on my mind lately because I listened to the audiobook version on the way down to LA last week. (Read by David Straitharn, who was, as you would expect, awesome.)
After hearing the book I knew it differed substantially from the movie so I went to wikipedia to track the difference. But that only increased the level of complexity because apparently the audiobook was abridged. Sheesh.
On the bus tour I mentioned to somebody I'd just listened to the book and they asked about the "Rolo Tomasi" part, and I had to tell them it wasn't even in the book. And Wikipedia confirms that it wasn't included in the unabridged book either.
Reading the wikipedia entry really made me appreciate what a fantastic job Hanson and Helgeland did on the script. They were really true to the characters but compressed and extracted a much leaner (though still quite complex) plot. I think it's actually superior to the book, in most respects.
Some interesting tidbits about the production gleaned from the wiki entry:
To give his cast and crew points and counterpoints to capture L.A. in the 1950s, he held a "mini-film festival", showing one film a week: The Bad and the Beautiful because it epitomized the glamorous Hollywood look; In a Lonely Place, because it showed the ugly side of Hollywood glamor; Don Siegel's The Lineup and Private Hell 36, "for their lean and efficient style";[5] and Kiss Me Deadly, because it was "so rooted in the futuristic 50s: the atomic age".[2][5] Hanson and the film's cinematographer Dante Spinotti agreed that the film would be shot widescreen and watched two Cinemascope films from the period: Douglas Sirk's The Tarnished Angels and Vincente Minnelli's Some Came Running.
Before filming took place, Hanson brought Crowe and Pearce to L.A. for two months to immerse them in the city and the time period.[7] He also got them dialect coaches, showed them vintage police training films and had them meet real cops.[7] Pearce found the contemporary police force had changed too much to be useful research material and disliked the police officer he rode around with because he was racist.[8] The actor found the police films more valuable "because there was a real sort of stiffness, a woodenness about these people" that he felt Exley had as well.[7] Crowe studied Sterling Hayden in Stanley Kubrick's crime film, The Killing "for that beefy manliness that came out of World War II."[5] For six weeks, Crowe, Pearce, Hanson and Helgeland conducted rehearsals, which consisted of their discussing each scene in the script.[9] As other actors were cast they would join in.[5]