You may be disappointed at the engine's ability to respond to the throttle. If the flywheel is heavy (and it likely is) the engine will not rev fast enought to give snappy acceleration.
When I was considering modding a lawn tractor engine. I took a Craftsman I had for a spin in 5th gear- what a dog! An 11 hp dog.
Like a St. Bernard- not a greyhound.
Check out the weight too. Another St. Bernard attribute.