offroadunlimited.com has a pretty good price for shock tabs at $7.00 a pair and 3"x3" spring pads for $27.50 a pair. I have read that the 3" pads can be used on the 3 3/8" axle tube.
I tried to search for A-A Manufacturing but don't come up with anything.
You might also want to call a local hot rod store - mine has various spring pads available for pretty good price.