The tunnel Biff drives through in the opening scene was used as the entrance to Toontown in Who Framed Roger Rabbit (1988).
The first credited on-screen role for Richard Egan. His only previous appearance was an uncredited part as a police detective in The Story of Molly X (1949).
Biff and the boys invoke "Niatpac Levram", which is "Captain Marvel" spelled backwards. As fans of the comic know, Niatpac Levram is the Captain's mirror duplicate, who first appeared in Captain Marvel Adventures #139 in December 1952 ... about 2½ years after this movie premiered.
The Three Stooges' most frequent guest co-star Vernon Dent makes an appearance on the park bench, losing a shoe.