OEM Firestone air springs are no longer available and the aftermarket oem springs don't get a lot of positive recommendations. Mark Grueninger made a set of adapters to use a current Firestone 9294 spring. His post is here.
Thanks to Mark I set out to make a set like his.
From Ebay I got steel discs for $10 each and combined shipping of $16.
R&S Leafspring had the best price on the springs.
test fit all the way up
test fit all the way down