Yes I put set from www.choppershox.com on slacker john bike but I did what motorcycleguy did and replaced the spring with cut down springs from the top spring of a springer.
The springs that came with the shock kit were rated at 300 psi each and they did not move with me standing on they and jumping on the seat. The little I drove the bike they work great

look here
www.flickr.com/photos/750chop/page2/