The all-original 1966 Impala sitting right here in front of everybody’s eyes is powered by a matching-numbers 396 with a 400 transmission. The engine has never been rebuilt, it’s still the one installed by Chevrolet when it built the car, and it’s starting and running properly.
The car doesn’t necessarily come in the best condition, but this isn’t exactly a surprise given the Impala has been sitting in a garage since 1981. That’s what the Craigslist seller says, at least, though they claim this ’66 Impala has also won some prestigious prizes for how original it still is.