After graduating in 1943, Gibron joined the United States Marine Corps during World War II. Gibron left the military as the war ended in 1945, however, enrolling at Valparaiso University in Valparaiso, Indiana. He played his freshman year of college football there and was captain of the team, which finished the season with a 6–1 win–loss record and won the Indiana Intercollegiate Conference championship under head coach Loren Ellis. Gibron was named an All-Conference guard and was an honorable mention Little College All-American.