In order to get distribution for his film, Martin Scorsese was told to add nude scenes so it could be promoted as a sexploitation film. He shot the fantasy scene showing J.R. imagining encounters with prostitutes.
A scene with Harvey Keitel laying on a bed while "The End" by The Doors is playing in the background almost got repeated in Apocalypse Now (1979), though in different circumstances. Keitel was the original choice for the Willard role (played by Martin Sheen) in Francis Ford Coppola movie but was fired a few weeks after some rehearsals, and as known to many, the film starts with Willard lying on a bed with The Doors song playing in the background.
First in a trilogy of films in which Harvey Kietel stars in the lead role for a debut for a future acclaimed director. This with Martin Scorsese, who went on to achieve acclaim for Taxi Driver & Goodfellas. With Ridley Scott in The Duelists, who went on to make Alien & Gladiator. Finally with Quentin Tarantino in Reservoir Dogs, who achieved praise with Pulp Fiction & The Hateful Eight.