I see you have a 48 gmc, me too. I wonder how close the VIN # are. I think mine was a southwest truck so maybe built in CA. If you're sure of build location our numbers might be pretty close? My VIN is FC2533048. I think the last are the sequential numbers.
I reworked my front springs with new pins and shackles from Eaton Spring. If you have unmatched ones that's a different story. St Louis Spring gave me a good price for new ones with pins already installed which is nice but I had already bought those parts so I just reworked the ends. Should have checked local first. I live is st Louis so shipping would not have been an issue, good luck on the truck Jim D


pictures below
https://picasaweb.google.com/111413431667404132006
Jim D - '48 GMC 1ton pickup