Jim Dunaway, selected ninth overall in the second round of the 1963 AFL Draft from Ole Miss—where he was a consensus All-American and national champion—joined Western New York as a highly regarded interior lineman. Playing next to Tom Sestak, Dunaway quickly proved himself to be a powerful, relentless tackle who contributed to one of the most formidable defensive fronts in professional football history.

Dunaway had remarkable strength and lateral agility for his time. Playing as a left defensive tackle, he was adept at filling A-gaps, overpowering offensive guards, and disrupting running plays early. His skill in resetting the line made it hard for opponents to set up an inside run, and his strength in collapsing the pocket often pressured quarterbacks into hurried throws.

Dunaway was a central force behind Buffalo's dominance in the mid-1960s, helping lead the franchise to consecutive AFL Championships in 1964 and 1965. He was a core member of the legendary Bills front seven, which set an All-Pro football record by holding opposing ball-carriers to zero rushing touchdowns for 17 consecutive games across the 1964 and 1965 seasons.

During his peak, Dunaway received four consecutive AFL All-Star selections (1965–1968) and was honored as a First-Team All-AFL selection in 1966. His interior presence enabled Buffalo's defense to maintain a consistently leading position in the league concerning points and yards allowed during the AFL's prosperous years.

Following nine seasons in Western New York (1963–1971) and accumulating 126 regular-season appearances with the Bills, Dunaway's tenure concluded prior to the 1972 season when he was released by Buffalo. He was promptly acquired by division rival Miami, where he spent his final NFL season as a primary rotational tackle on the undefeated 1972 Dolphins team that secured victory in Super Bowl VII.

With the Bills, Dunaway played 126 regular-season games (114 starts), won 2 AFL Championships, earned 4 AFL All-Star selections, 1 First-Team All-AFL honor, and recorded 22.5 unofficial sacks along with 12 fumble recoveries.