Kowalczyk attended Westfield High School, where he earned four letters in football and baseball, three in basketball and two in track.
As a sophomore, he was given the nickname "The Sprinting Blacksmith", after his efforts helped his team defeat UCLA in the 1956 Rose Bowl.
As a junior, he was limited with a serious ankle sprain he suffered during fall practice and only registered 128 yards and 2 touchdowns.
[3] Kowalczyk spent six weeks with the Detroit Lions in training camp, before his rights were sold to the Dallas Cowboys.
Although he initially refused to report to the team, he changed his mind after commissioner Pete Rozelle threatened to fine him.
He was a member of The Pigskin Club of Washington, D.C. National Intercollegiate All-American Football Players Honor Roll.