PP77 Spring Code - 2012 XLT - 500lb Payload Pkg?

[np342403]

I recently purchased a 2012 Expedition XLT. The dealer said it had the 500lb payload pkg. I didnt look into it much at that time, but I am wondering now for my own knowledge. What does this package actually consist of? Is it only different rear springs? The spring code on my door jam sticker specifies "PP77." Any thoughts? I tried searching but cant find this exact spr. code listed anywhere.

 

[dragosa]

Hey i am also trying to figure out the pp77 spring code on my XL SSV model