A 5 feet 8 inches (1.73 m) tall guard, Hennon was noted for his prolific scoring ability and is a member of the Helms Athletic Foundation Basketball Hall of Fame.

During his high school days he set a Western Pennsylvania Interscholastic Athletic League four-year scoring record (1951–55) of 2,376 points that endured until 1993.

Hennon's basketball career was highlighted by a 1957 contest where he scored a school record 45 points (scoring on 20 of 42 field goals and 4 of 5 free throws), leading Pitt to an 87–84 double-overtime victory over Duke University.

The 1958 AP First Team All-American team consisted of Hennon and four Naismith Basketball Hall of Fame inductees: Guy Rodgers Temple, Elgin Baylor Seattle, Wilt Chamberlain Kansas and Oscar Robertson Cincinnati.

[4] Hennon was named to the East team, coached by Adolph Rupp, of the 1959 East-West All-Star Contest.