I have a Quigley van, and on mine, the whole spring assembly is stock from the van (2WD econoline). If you fill out the help form with the VIN on the Quigley website, they usually get back to you within a few hours, and can provide the full BOM from the build.
If it is the stock assembly from the van, you can follow the previously posted ebay link, or put the van model and year into the website of your favorite car parts dealer to find the right parts. If you really get stuck in customs hell, I can drop ship some from Autozone for some wine
By the way, I went with slightly stiffer springs, and I no longer bottom out on every slight bump in the road. I would highly recommend that if you end up having similar problems:
https://www.sportsmobileforum.com/fo...tml#post315360