* Small Block V8s: These were the most popular choices. Sizes included the 350 cubic inch (most common) and the 307 cubic inch. Various horsepower ratings were available within each displacement depending on the carburetor and other components.
* Big Block V8s: While less common than the small blocks, the 454 cubic inch big block was an available option, offering significantly more power.
Therefore, there's no single answer. You'd need to check the vehicle's documentation (like the original build sheet, if available) or the VIN to know for certain which engine a specific 1971 El Camino SS had.
