Leaf springs sagging after recall? Next move?

Hi I just purchased an 07' double cab long bed with 4x4 back in June. At the used car dealership they showed me the carfax and the carfax said the leafspring recall replacement happened back in April (so just 2 months before me buying, sitting on the dealership lot the whole time). I confirmed by entering VIN into toyota website. I looked at the leafsprings and was stoked to see that they looked brand new. That being said, they are flat.

I'm going to upgrade to bilstein 5100s soon (better than the 4600s for towing I've read). I want to stick to stock height because it's supposed to maximize towing capacity. I'm wondering if maybe worn factory shocks are causing the leafsprings to sag and once the new shocks are installed if the sag/flatness will go away? I want to use the truck to tow wood and will have at least 600 pounds of work gear in the bed at all times. Would be a shame to waste the life of the leafsprings that just got installed, so I'm wanting to just add a leaf for now and then if leaf springs go bad in the future get aftermarket leafs at a later time.

What do y'all think?

 

I have 5100,s on all 4 corners with factory springs . I find the ride very rough up front as well as on the rear .

 

Worn Shocks won’t make the leafs sag. Although if they are doing a poor job dampening eventually the bouncing will over work the springs and tire them out.

Factory springs are crappy. If you want to tow you could add a leaf (budget option) or get a proper aftermarket leaf pack.