As far as I know, John Olson is still around. I dealt with him last year. He seems to be a one-man band so rapid response is sometimes difficult for him. He does know spirngs, however.
I have experimented with the springs, bushings, and shocks. (It's a hobby.) Anytime you mess with the springs, ride height is going to be an issue. Getting the front and back the way you want it is delicate. The easiest changes are the shocks. I like the Koni Classic adjustable shocks. They let you experiment and change your mind. Depending on condition you may want to replace all the rubber bushings. Urethane adds significant stiffness. Springs are the most difficult to get right. That's where John comes in. He has one solution for progressive and one for sport. If you want to be adventurous, Coil Spring Specialties (
www.coilsprings.com) will work with you to make anything you want. Just be prepared to install and re-install multiple times.
