There are many good stories from the novel--Luca's, Neri's, Sonny's rise, the Bocchiccio's and how they helped Michael--that made the novel all the more pleasurable. But I don't think that the movie, long as it was, suffered by not including them.
Ntra la porta tua lu sangu � sparsu, E nun me mporta si ce muoru accisu... E s'iddu muoru e vaju mparadisu Si nun ce truovo a ttia, mancu ce trasu.