TSB Leaf Springs?

I have read many posts on this and sorry to ask more? I have a 09 double cab 4x4 Long Bed TRD sport That seems to ride ok. I have not put much in the bed yet but plan to once and a while. I have the 3 leaf spring set up and drives smooth will the new set up make it a stiffer ride? What about when nothing in the bed how is the ride? I do alot of highway driving so like 75% of the time nothing in the bed. My dealer said I should wait till my 1st service to have it looked and said to tell them about the problem . I only have 1,000 miles on the truck. So far I love the truck so much better than my 05 ford f150 that was to much truck than I needed.
Thanks

 

They told me that it would make the ride stiffer. I actually thought the ride was better afterwards. Go luck with it.

 

When I got my TSB done on my 08 i got my shocks and struts done also since you have the TRD its just your springs so don't worry about anything As far as the ride i didn't feel a diffrence.

 

YeAh I just had the TSB done to my sport TRD on Monday. I haven't felt much difference except for when I go over bumps my truck feels more stable and the back end feels more solid and doesn't wobble from side to side anymore.
I would get it done IMHO.