This was only eight yards short of Eric Allen's NCAA record of 350 yards, set two years earlier in 1971. Leaks was again named All-SWC, as well as a consensus All-American. He finished third in the Heisman balloting, which made him only the fifth Longhorn Heisman finalist and tied him with James Saxton's 1961 performance for the best Longhorn Heisman finish. Texas went 8-3 in 1973 and won another Southwest Conference title and were ranked eighth, but lost the Cotton Bowl 19–3 to #12 Nebraska and finished fourteenth. Following his success, Leaks was an early Heisman favorite for the 1974 season, but suffered a serious injury in spring drills when he leaped into the air and another player's helmet hit his knee. It required surgery and Leaks was given the option to take a redshirt season. He chose to play, but missed the first game and was hobbled by injuries all season. Freshman Earl Campbell was given the majority of carries and was the team's leading rusher and bowl MVP that year. Leaks carried the ball 96 times for 409 yards and 4 touchdowns. Texas was 8-3 in the regular season but were runner-up to Baylor in the Southwest Conference. The #11 Longhorns lost 27–3 to #6 Auburn in the Gator Bowl, in which Leaks did not play, and fell to seventeenth in the final poll. Leaks was selected in the fifth round of the 1975 NFL Draft by the Baltimore Colts. He played five years for the Colts, putting up 1,268 yards and 14 touchdowns, but he spent most of his fifth season on the sidelines after the Colts added former first-round choice Don Hardeman. After the 1979 season, he was waived by Baltimore and picked up by the Buffalo Bills, where he spent four years carrying the ball and blocking for Joe Cribbs. He was considered one of the best blocking backs in the NFL and went to the playoffs 5 out of 9 years. At training camp of his tenth year he was cut by the Bills in August 1984. At that time, only one running back from his class, Walter Payton, was still playing. Leaks and his wife had been working in the real estate business for several years before his football career ended and he transitioned into it full-time. In 1987, he began working with Texas General Land Office in Austin, eventually becoming the Director of Veterans Land Board Appraisals. He retired from that job in 2013.