This engine has a standard 1" keyed shaft on it. You might be able to use a Briggs 10.5hp or 12.hp if you can come up with a muffler to fit the new engine. The engines over 8hp have a 1" pipe threaded port and the 6-8hp have a 3/4" muffler port. There is no guarantee that these larger engines will work for you without changing the muffler.
