Contact Hygear Suspension (outside of Ithaca NY). They can rebuild/revalve/setup with new spring. Had them rebuild my front works shocks to my size and riding abilities and they are phenomial.

At the time I had the front done I inquired about the rear. They said stick with the stock rear and they can rework it to make it perform well.

This winter I am rebuilding the swingarm. All new bearings, sprockets, sliders, new chain, and I'm going to have my rear shock rebuild by Hygear.