Bob Steele's character name is Duffy. He also played a character named Duffy two years earlier in F Troop (1965).
This project was originally set up at Paramount in 1967, and Rex Harrison and Melina Mercouri were being wooed to star.
This was the third collaboration for Zero Mostel and Akim Tamiroff in less than 24 months. They had both appeared in Great Catherine (1968) and the canceled Seth Holt comedy "Monsieur Lecoq".
Scripted by William Peter Blatty, who later gained fame and fortune as author of the novel The Exorcist.
"The Great Bank Robbery" was filmed on location at Columbia, CA.