What is the horsepower of a 1971 400m Cleveland engine?

The horsepower of a 1971 400 cubic inch Cleveland engine varied considerably depending on the application and options. There wasn't a single horsepower rating. It ranged from approximately 200 hp in base models to over 300 hp in higher-performance versions found in some muscle cars. To know the exact horsepower of a specific engine, you'd need to know the vehicle it was in and its specific options.