I understand that you are trying to do this on a budget, but your methods somewhat baffle me.
Why not save some money and purchase the lift springs and go that route? by the time you done fiddling with your 32 year old springs, replacing all the bushings, sourcing other springs, your gonna end up with some thick spring packs to get 2.5" of lift that will ride horribly. adding one leaf won't effect the ride as much, but 2 or 3 leafs will.
Plus for cost reasons factor in purchasing shocks, new u-bolts, new spring clamps, brake lines, etc.. why not just buy a quality kit and go from there.
You can get a quality 2.5" lift kit for your 5 for anywhere between $300 and $800. look at superlift, rancho, OME, skyjacker. all kits should be comprehenisive and complete.