Nice film but the "epic" tale of the banda della Magliana is so huge that the runtime of a movie is not enough. If you can I suggest you to watch the TV series quoted by Sterling McGarvey. Produced by SKY Italia a couple of years ago the series is more gritty and similar to the 70s italian crime movies style.
Although many Italians swear by the television series that came after this film, it's a great gangster film that depicts crime in the 70s without the Mafia preconceptions that color Hollywood's idea of Italian crime films. Well-edited, well-paced and full of great performances.