Standing 6'4", he was the long-time stand-in for
John Wayne (1941-1952).
They often played chess together on the set between takes and were good
friends off-set (Wayne bankrolled Davis' first instructional film,
The Dangerous Stranger (1950). Once, when the stand-ins were called back to the set and Wayne
wanted Davis to finish his move, Duke went to the set himself and stood
in for his own stand-in.