How much horsepower does a 1969 4v 351 windsor have?

The horsepower of a 1969 4V 351 Windsor varied depending on the application and the specific options. There wasn't a single, universally stated horsepower figure. However, a common rating for a 1969 4V 351 Windsor in a Mustang or other similar application was 290 horsepower. This could be slightly higher or lower depending on the specific carburetor, exhaust system, and other variables.