During 1960, Chevrolet had been a strong contender in both drag racing and NASCAR competition, however, more horsepower and additional performance development were necessary for continued success on the track. When released, the new '409' may have outwardly resembled its predecessor, the 348 'Super Turbo-Fire,' but it was in fact based upon a completely new cylinder-block design. It received forged pistons, a forged crank, a six-quart oil pan, 11.25:1 compression, high-strength connecting rods, and slightly modified heads from the 350-horsepower 348. Additional refinements included a new camshaft and revised valvetrain, plus a new aluminum intake manifold mounting a Carter AFB carburetor. The new RPO 580 490 CID V8 was announced on December 17th of 1960 and delivered 360 horsepower. It was introduced alongside the new Super Sport appearance option and production of the SS package and 409 motor followed in January 1961. Early 409s were earmarked for NASCAR teams first and drag racers were forced to wait for the new engines until after the Daytona '500' was run. The list of top drag racers who built their legacy and reputations with the 409 included Dave Strickler, Bill Jenkins, and 'Dyno' Don Nicholson. The 409 even became a pop-culture icon as the subject of the Beach Boy's 1962 hit song '409.' The era of the 409 would last through 1965, when it was replaced mid-year by the 'Mark IV' 396.

Standard equipment included a cigarette lighter, electric windshield wipers, dual sun visors, black tubeless tires, front armrests, foam seat cushions, and a Deluxe steering wheel. The base engine was an overhead valve 235 CID six-cylinder unit that had four main bearings, hydraulic valve lifters, a Rochester one-barrel carburetor, and delivered 135 horsepower at 4,000 RPM. Eight-cylinder engines included a 283 CID 230 hp, 348 CID V8 with 250 to 350 hp (depending on configuration, compression, and carburetion), and the 360 horsepower 409 CID V8.

Although the 1961 Bel Air wore new styling, it continued to use the 119-inch wheelbase of its predecessor, but its length was slightly reduced to 209.3 inches. Prices began at $2,380 for a six-cylinder two-door sedan, while the V8 added an additional $110 and reduced weight by approximately five pounds.