Even if you rearch the springs ,they will eventually loose their load carrying capability. I do belive rearching springs shortens their life. Toyota uses lots of thin leaves thicker leaves are what you need to support that wheight, This is why cyoteefrog suggested f-150 springs.
![My Two Cents :twocents:](https://board.marlincrawler.com/Smileys/marlin/twocents.gif)