Deriving its name from the African antelope of the same name, Chevrolet's most expensive passenger model through 1965 had become the best-selling automobile in the United States. The 1963 Impala featured rectilinear styling with an engine-turned aluminum rear taillight panel surrounded by a chrome border on SS models. Engine choice was similar to 1962, with the small-block 283-and-327-cubic-inch (4.6 and 5.4 L) V8s most popular. The Sport Sedan featured a new, creased roof line. A new "coved" instrument panel with simple indicator lights for hot and cold engine conditions. An optional factory tachometer was built into the dashboard, just above the steering wheel; it was rarely ordered.