Unable to find white suits large enough to fit Chuck McCann, costumers had him wear old suits previously worn by studio character actor Sydney Greenstreet.
To conceal her age, Sondra Locke falsified her birth year more times than such notorieties as Joan Crawford, Mae West or Zsa Zsa Gabor. When Heart was being made in 1967, the late actress (born Sandra Smith in May 1944) was 23 years old, but an international press release said she was 17. Nashville Tennessean theater critic Clara Hieronymus called her out on the lie almost right away, but it took decades for the mass media to catch on. At the time of the movie's 1968 premiere, Locke claimed to be 21 but was in fact 24. While promoting The Outlaw Josey Wales (1976) eight years later, the then 32-year-old gave her age as 20. Various news outlets wrongly reported Locke as being 29 in 1978 (when she was 34); 26 in 1979 (35 then); and 30 in 1980 (actually 36). Her real age was finally confirmed by her maternal half-brother, Donald Locke, in an exclusive interview with The Tennessean in 1989. Sondra Locke was 45 in 1989, but her publicist claimed 42. Locke never came clean about her age, even lying about it in her autobiography, and she refused to back down despite the proliferation of fact-checking during her final years. In a 2015 podcast interview, the then 71-year-old lied that she "was just graduating high school" when she started work on this film. Locke graduated high school in May 1962 at age 18 - more than five years before she was cast in this film.
The fire department of Selma, Alabama where a lot of this picture was filmed, lent its new fire engine with an 85-foot crane for director of photography James Wong Howe to use for the Ferris wheel shots.
The balcony scene in the restaurant / hotel where Singer and Spirmonedes had lunch was shot in the Hotel Albert in Selma Alabama.
The Hotel Albert was built in the 1860s. Union troops used the building as a headquarters after the Battle of Selma in 1865. The building was demolished in 1969, a year after the movie was released.