http://www.jcwhitney.com/autoparts/...1/p-2015541/N-111+200750871+600003421/c-10101 is this what your talking about for leaf springs???
not really, facelessnumber did an article on how he bought a couple leaf setups off an e-150 at the junkyard then took some leafs out. i have now done it also and so far it seems stiffer, but i cant really say 100% until i get my shock tower fixed and drive it. i still have several leafs left though if i need it stiffer.
I like the E150 idea and might try it on my next spring swap. If you're looking for cheap, I'd go that route. The air shock idea might cost you more in the long run unless you fab up a brace. SVTHAULN has a Comet that has a brace. It looks great. I looked into having springs re-arched in Tulsa earlier this year and it was MORE EXPENSIVE than buying new ones from General Spring in KC.