According to Carl's cycle, the slp single had a 3 sled length advantage over stock. As far as clutching goes, this is what are set up is here in Washington at 4-6000. Stock helix and springs and 66 gram weights. That is on a sled that has slp single and v-force reeds. It works great, but I would think there is room for improvment. A guy just has to mess around with a steeper helix and some different springs and weights, to see if you can get a little more out of it. At any rate, in my very humble opinion, the stock clutching ain't to bad.