In the opening, Gallo is sitting in a theater watching a black-and-white film repeating the dialogue of one character. The film is Kiss of Death (1947) and the character is Tommy Udo, played by Richard Widmark. This was Widmark's breakout role, the one that made him a star. Joey Gallo is said to have adopted the fictional Udo as his role model, an example of life imitating art.
Carmine Caridi also appeared in The Gang That Couldn't Shoot Straight (1971), which was also based on Joe Gallo's life.
The film is not related in any way to Joe (1970), also starring Boyle as a character named Joe.
Sam Coppola and Tony Lip would both go on to star in The Sopranos (1999). Coppola as Dr. Melfis family therapist, and Tony Lip as Carmine Senior. Peter Boyle, who plays the title role, would go on to star in Everybody Loves Raymond (1996), which also starred David Proval, who played Richie Aprile in The Sopranos.