Reb Brown, who played Elmo Hacker, was a Los Angeles Sheriff's Deputy, a professional boxer, and while playing football for USC in 1967 lost his starting running back position to O.J. Simpson.
The scene where Elmo knocks on Mr. Furley's door, Merl wakes up and turns the light on right before Elmo starts knocking.
First episode to feature to feature Ralph's name in the title