There are several variations of the Ford 351 Cleveland engine, all of which range between 240 horsepower and 330 horsepower. Each engine was built and produced by Ford from 1969 to 1974.
The Ford 351 Cleveland engine was introduced in 1969 as a performance engine. Throughout its 5-year run, the engine was revised to offer the most power possible.
The M-code engine was produced between 1970 and 1971. It produced roughly 300 horsepower.
The most powerful of the series was the R-code Boss 351 engine. It was built with a high compression ratio of 11.7:1, and it managed 330 horsepower to the crank.
The last of the series produced was the Q-code engine. It featured a lower compression ratio, which decreased its power output to approximately 250 horsepower.