This wonderfully titled American Cinematheque tribute to the Italian westerns that made Clint Eastwood a major star and director Sergio Leone and composer Ennio Morricone international celebrities is so big that it's taking over both the Hollywood and Santa Monica branches of the Cinematheque. At 7:30 p.m. Friday at the Egyptian Theatre, see the two films that started the trend: 1964's "A Fistful of Dollars" and the sequel, "For a Few Dollars More." The first starred Eastwood in a shameless remake of Akira Kurosawa's "Yojimbo," while the second paired him with the sinister Lee Van Cleef. At 7:30 p.m. Saturday at the Aero, lose yourself in Leone's two-hour-and-45-minute "Once Upon a Time in the West." Charles Bronson, Henry Fonda and Jason Robards star as three of the least trustworthy men this side of the Via Veneto. And Claudia Cardinale has a few tricks up her sleeve as well.