1963 Impala Z11 427
Chevrolet’s famous 409 engine was immortalized in the song of the same name, dating from 1962, and matched the desire of many muscle car enthusiasts in the early 60s. In 1962, the hot configuration was to order the 409 in the Bel Air “bubble roof” 2-door hardtop
. Well, taking it a step further in 1963, Chevrolet introduced the Z11 option for its Impala lineup. The package included a modified 409 increased to 427 cid by means of a manoeuvring crank, as well as special heads, valves and a two-piece aluminium intake manifold with double quadrilateral. Production was rated at 430 hp. The additional features of the Z11 were not limited to the engine compartment, however, the hood, fender bumpers and other elements were made of aluminium in order to lighten its weight in running order. It was a set of RPO (standard production option) supposedly available to the general public, but it seems that it was only selectively sold to racers to advance Chevrolet’s cause on the track. Anyway, the Impala SS of 63 with a standard 409 of 425 hp was fast enough for an average joe,regularly turning under 15 years to the quarter of a mile. Only 50 or more (quantities vary depending on the source) The Impala Z11 was sold in 1963, and there are 7 that still exist.