What is the goal? Are you looking for stronger, more/less height? I have a '55 and just put on the wagon springs (5-leaf pak) and it raised the rear about 1 1/2" and is much stiffer than the sedan 4-leaf. There are 2" lowered springs, too.
Give us information on what you want to do and I'm sure there is help here.
building a 57 gasser w 37 chevy straight axel, planning a big block w radiused rear wells. went to start on it again this spring but when I took it off jack stands the rear settled down . upon looking the springs are junk. should have know the car sat in a field 26 yrs.. 46 austin says they are plentiful and cheap .. not around my are. Thanks for input may have to break down and buy new but do not want it high in the rear..