I have the FL3Z5560-C rear leaf springs on my 2017 5.0 SuperCrew. My neighbor has the FL3Z5560-A on his 2016 3.5NA SuperCrew. A 2019 2.7 ECO SuperCrew also uses FL3Z5560-A. Does anyone know all the specs on the -A, -B, -C, -D rear ford leaf springs? Looking for load capacity and lengths to know if I can interchange them. The 5.0 I assume was built for high payloads. But I want a smoother ride so wanted to interchange to a weaker spring. I am also good with dropping the rear an inch or two. I have to crawl around the vehicles to make sure I properly match shocks to the different rear leaf springs as well.
I can't get use to the rough ride of my 17 5.0 as compared to my 01 K.Ranch. While a damper change may help, I want the effectiveness of placing 500 lbs at my tailgate my using a spring with a 500 lb lighter capacity. I will leave the front AS-IS since it holds engine weight.

 

i would not use oem ford shocks. They're just really not good when the truck isn't loaded with some payload. I know people talk about the bilstein 5100's all the time but if you can't get those get something comparable. The rebound is far too slow on the oem ford shocks resulting in a lot of rear end hopping and walking around when driving and hitting bumps.

 

This forum showed me the issues with the stock shocks. Bilstein recommended 4600 series for stock height and no leveling. Just did rear and the ride improved. Has anyone done this in stages to know if the front shocks changed improves ride anymore than just the rears alone?