When the bartender asks Harper if he wants a "coonass" beer, he means a Cajun (or local) beer.
During post-production, director Stuart Rosenberg hired composer Charles Fox to do additional scoring, integrating the composer's melody "Killing Me Softly With His Song", into the movie. The song had been a #1 hit two years prior, while Fox was scoring Rosenberg's previous film, The Laughing Policeman (1973).
Paul Newman once said of the Lew Harper character in the "Paul Newman: A Life" (2009) biography by Shawn Levy: "I simply adore that character because it will accommodate any kind of actor's invention . . . It's just lovely to get up in the morning, it's great to go to work because you know you're going to have a lot of fun that day".
Lew Harper (Paul Newman)'s fee was $150 per day plus expenses, which had increased by $50 from his fee in the first film, Harper (1966).
This marked a re-teaming of Paul Newman, Joanne Woodward and Anthony Franciosa, all of whom appeared in The Long, Hot Summer (1958).