I don't rock crawl or want to bury it in a mud hole, i don't need that high of a ride height. I've always raced sport quads and that's the kind of riding i still like to do, fast. We ride local tracks and trail's here in Ohio, Hatfield, etc. I want to be lower for more stability and cornering. I recently upgraded from a 900 xp and ran 27s with no ground clearance issues thereOverall final drive will be lower, and you'll probably need to add a little clutch weight, but other than that, you're not going to have any ill effects from it, other than the obvious things like lower ground clearance and the like. It will actually be easier on the machine overall.
One still has to ask...why? I'm sure you have your own special situation for wanting to do it, but I'm curious as to what it is