Not sure what they are out of, but being from a drag sled, and looking at the shape of them, they were probably used with a relatively high angle helix with a large angle split and a light spring. All of the weight added to the tip like that will make for a more aggressive upshift at the top end. Good setup for drag racing and light sleds, but not so good for trail riding and/or heavy sleds. With the light secondary spring and high helix angle, the backshift would not be good for trail riding.
Just searched that part number, and it is used as an alternate setup for a lot of the Mountain sleds. Since the weight is so light, I would suspect that they are used for the very high altitude settings. The lighter weights will help keep the RPMs up at high altitudes. Kinda does the same thing as a stiffer spring in the primary, but the shape the the weight will have an effect on which part of the upshift is altered the most. Less weight on the pivot end will increase the early shift RPM and less weight at the tip will do the same for the later shift RPM.
