Chevrolet restyled the Impala for 1967, refining the styling introduced in 1965, considered its 'Fourth Generation' of styling updates. The early 1960s full-size Impalas and lightweight Biscaynes had ruled the strip, street, and NASCAR ovals. As the 1960s continued, their perch atop the performance ladder was replaced by muscle and pony cars. The performance credentials of the Impala continued to remain impressive, with the enlarged 427 CID Mark IV V8 becoming available in 1966, supported by an ever-expanding list of heavy-duty powertrain and suspension options to cope with the dramatic increases in output. 1967 Chevrolet Impala V-8 engine, automatic transmission, power steering, chrome and aluminum accessories, headers, new dual exhaust with Flowmaster style mufflers and X-pipe, aftermarket gauges, staggered 17" and 18" aluminum Coy wheels.