Originally Posted by WE3ZS

Hey Chris, The whole issue with the SDtrucksprings vs OEM ratings centers around what SD..... had decided to call their replacement springs vs what Ford has established as their spring code rating system, they just aren't the same. As stated in the threads that you linked to SD..... uses the same part number (calling it an "X code") for several applications where the various different Ford codes were originally used. And the advertised rating for those springs is more in line with what Ford's rating was for their V codes. Pretty confusing for sure! Now from reading the post swap measurement from members who have used those aftermarket springs it sounds like they were getting more ride height improvement than what would have been expected from Ford's actual V codes, so the plot thickens.
I did a complete spring swap on my EX and decided for the money being spent (in the end I got very lucky with that!) and how important it was to me to get exactly what I was planning from the swap that only OEM springs would do for me. The misleading and apparently incorrect ratings listed on SD.....'s website left too much in question for me as to what exactly I should expect from their springs. I was extremely fortunate to have a set of X/B OEM take-off springs gifted to me by a co-worker and those springs (with my mods) delivered exactly the amount of ride height increase and performance that I planned for and expected based on the OEM specs.
And for what it's worth I have collected spring info from several sources over time but mostly from members here and my info shows some different ratings than what was provided in the earlier posts in this thread.

This is what I have collected on Ford's front leaf spring codes:
S codes = 4000lbs capacity, 370 inch/lbs, 4.34" travel.
B codes = 4100lbs capacity, 330 inch/lbs, 5.02" travel.
C codes = 4300lbs capacity, 350 inch/lbs, 5.01" travel.
T codes = 4400lbs capacity, 390 inch/lbs, 4.63" travel.
D codes = 4700lbs capacity, 380 inch/lbs, 5.14" travel.
U codes = 4800lbs capacity, 410 inch/lbs, 4.89" travel.
V codes = 5200lbs capacity, 430 inch/lbs, 5.13" travel.
W codes = 5600lbs capacity, 450 inch/lbs, 5.34" travel.
X codes = 6000lbs capacity, 470 inch/lbs, 5.54" travel.
Capacity is per set.

Originally Posted by Lemonhead123

Sorry to revive an old thread but i was hoping for some help. I have a 1999.5 F250 with the 7.3 in it. My truck has a 3.5 inch lift kit on it from Tuff Country. Unfortunately the kit is a little too tall for my liking. I was thinking about taking the bottom leaf out of the pack to hopefully get closer to a 2.5 inch lift compared to stock. Tuff Country told me these specific springs have a spring rate of 605LB per inch. Can anyone help me figure out what the capacity would be and if taking one leaf out of the 5 leaf pack would be safe? Thank you all for your help!