The 97SPX waterbox flows better and some guys like the 98SPX wb too. The 95 XP 800 waterbox's are more restrictive then the 96's but both would have baffles come loose inside them sometimes, especially with salt use. When you see one that's been welded back together it's usually for that reason and not because of an attempt to upgrade. Old Yamaha GP waterboxes fit and flow well also. Many racers used to run those.