* 230 cubic inch inline-six: This was the base engine.
* 283 cubic inch small-block V8: Available in various horsepower ratings (e.g., 195 hp, 220 hp, and higher performance options).
* 327 cubic inch small-block V8: Also offered in various horsepower ratings, including higher-performance versions that were significantly more powerful. This was a popular upgrade option.
* 409 cubic inch big-block V8: This was a high-performance option, generating considerable horsepower and torque. It was less common than the smaller V8s.
It's important to note that the exact horsepower figures varied slightly depending on the carburetor and other specifications. The exact engine in a specific 1963 Impala would depend on its original build sheet or documentation.
