I ran the Goodwin Performance Clutch kit last year on my REV 440X, the clutching previously was stock and very lathargic..The kit raised the engagement, but not enough to wear belts too fast, I ran the same one all of last season. It made the sled much more agressive and quick, but lowered the top speed considerably. I would not reccomend this kit to someone who rides trail extensively or play rides in open areas (lakes etc). It works great for ditch riding and jumping, providing you with instant acceleration in tight quarters. Good luck! Frank.