I plan on doing the same thing. My bus is way oversprung for what I am going to be using it for. It was built to haul 22 people and I'm going to max out at 15. My springs are 3/8" thick and there are 12 of them. I have a local spring shop I am going to take the spring to and talk to them about what I can do to just remove and rebuild the original stack to make a softer ride and lower the stance. If you're interested in them they are:
http://www.gittspring.com/They built my leaf spring for my T-Bucket when I did that car years ago. They do some great work. I have to get one of the springs out and take down there to discuss my plans and then can go from there.
