Best V8 Leaf Springs??
I used the 340 XHD replacement springs. Assymetrical leaf placement to resist torque lift. While they have worked real well for me in street usage, using them will give you at least stock ride height on the stock hangers, so if you plan on lowering the car much aftermarket springs might be a better solution.
I can't say about current availability (as they say "your results may vari") because I got them from my local dealer before Obama took over CryCo and forced him to give up his franchise. He was known to donate heavily to the Republicans, but then we all know politics could NEVER have had anything to do with forcing the largest volume dealer in the state out of business.