Back in the '50s, it was typical for carmakers to apply a popular model name to a line of cars a few years later. For example, Chevy's first hardtop, introduced in 1950 was called the Bel Air. Three years later, the Bel Air name was used on all models in Chevy's fanciest series. This helped sell more cars because people raved about their 1950-1952 "Bel Air" and then Chevy made a whole range of body styles Vel Airs, so even the person who did not want a hardtop could still have a Bel Air.
During the '60s, the same game was played, but in a different way. The '61 Impala SS was launched as an option package, rather than a model. Then the 1964 model lineup offered a separate Impala SS series. Later, as interest in the big SS started to wane, it became an option package again.
The list of standard equipment on the '64 Chevrolet Impala SS took up where regular Impala features left off. Super Sport buyers got leather-grained vinyl upholstery, individual front bucket seats and swirl-pattern dashboard and body molding inserts. They could also store their gloves or sunglasses in a locking center console. Naturally, there were red "SS" emblems all over the cars. In addition, the doors carried red reflectors and neat-looking wheel coveres were included.
For 1964, due to the performance ban that GM brass put into effect the previous year, Chevrolet engine choices stayed about the same as in late 1963. Ban or no ban, that meant that the Impala SS 409 hardtop ($2,947) or convertible ($3,169) was still a big, fast car. The hardtop tested out at 7.5 seconds for 0-to-60 mph and 15.3 seconds in the quarter-mile.
The Turbo-Fire 409 V-8 was again available in three versions. The first had a single four-barrel carburetor and 10.0:1 compression. The second version, costing $428 extra, came with a single four-barrel carburetor, dual exhausts, a high-lift camshaft, solid valve lifters and an 11.0:1 compression ratio. The third 409 was a 425-hp version costing $484 extra. It had dual four-barrel carburetors, dual exhausts, a high-lift camshaft, solid valve covers and an 11.0:1 compression ratio.
In 1963, a total of 16,920 big Chevrolets left the factory with 409s under their hoods, but in 1964 orders for these engines dropped and only 8,684 were installed. That makes the 1964 Impala SS 409 much harder to find than a 1963 edition. In both years, most 409-powered Chevys were Impala Super Sports.