IMO, the best possible mods you can do to a rev are simple and make them handle WAY different and a LOT better when off playing in the woods.
cut the swaybar in half and get rid of it.. dont even think about it.
smittys drop brackets.
they help the sleds lay over SO MUCH... the summits are just a stretched out trail sled, so the geometry IMO is kinda dumb. the dropping the rear skid bolts down 2.5" made mine handle WAY better. they just carve a lot better
also, its possible to do the simple little rider forward(er) setup that moves the top of the steering post forward about 2-3" that combined with a small rise you get from the angle forward, it changes things up a LOT.. I love the geometry, and other then the drop brackets its all pretty much free.