I did replaced all of my leaf springs. They had flattened out completely and the tires would rub on the top of the wheel well when hitting bumps.
I bought mine from etrailer and did go up to 2400# springs. Mine were originally 1750# springs. I also added the Equaflex too. It rides like a dream and I havent had any problems since I replaced them. My axles are 3500# axles.
If you do go up to a heavier spring, from what I had researched, you can make the ride stiffer and thus the trailer will hit bumps pretty hard, which in turn puts stress on everything inside the trailer. Thats why I added the Equaflex to mine, to smooth out the bumps with the heavier duty springs.
Brian, Tamara, Abigail
2003 Lincoln Navigator Ultimate Edition 4X4
2004 Crossroads Cruiser CT30RL