it would help knowing the brand.
i'm assuming it's a Rockwood or Flagstaff.
also, posting in the Popup section would be a better place.
i seriously doubt there any info on the leaf springs. you could contact the axle manufacturer.
but could maybe find specs by knowing the brand.
Dan-Retired California Firefighter/EMT
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity