What horsepowertorque 400 Chevy engine?

Depends on the year, and what model it was installed in and if it is a big block 400 or small block 400. Need more information to provide an answer.

The 1970-1972 400's are the most desirable motors to find. The early ones produced up to 265 HP stock. Chevrolet did not make a big block 400, i believe the other answer is referring to the Pontiac 400, as it is considered a big block. These engines can be torque monsters with the right setup. I have a 1970 motor with fresh rebuild and a single plane edelbrock torker 2 manifold. I have not dyno'd this engine, but it is great on the street and fries the tires in my 70 Pontiac lemans.