I used my stock '37 springs for years, this last year I switched them out for new ones special made by Detroit Spring. I went with a softer spring rate for softer ride. If you plan on hauling stuff, stick with stock replacements. Also stick with stock width unless you plan to remake the whole spring setup. Changing the spring hangers for wider springs looks like a whole lot-a work thats not really needed.
Decide how you plan to use the truck before purchasing springs. Check the INFO packet from GM for stock spring rates and be sure to ask the seller of new springs what there rates are. I can tell quit a difference just going from 190 (stock ) to 140 spring rate on the rear.
