Nobody list stock rates, and the aftermarket doesn't list their rates. We're literally blind in this application when it comes to spring rates. You don't see many people concerned about spring rates either, it seems the big bunch is simply concerned with *** inches of lift so that's how the market reacts. if the amount of lift wasn't enough to satisfy the eyes then they'll recommend to add a bigger spacer, it seems we have 3/4, 1 and 1.5" in various flavors spacers for the rear coils. Then you have 1" springs, 1.5" springs, 3" springs and 5" springs, lol.
The difference in prices on the spacers is crazy, a spacer is a **** that gives you a little more lift when the aftermarket springs weren't enough to give you a better rate/height for your application and how much weight you add to it from unloaded to fully loaded. I run a 1" Daystar with my Icons but i've been researching for new springs. I don't like spacers. I have 450lbs extra in mods in the back of my truck so that's how i have to account for height in my application unloaded with my Icon springs. Would you pay $50 for a spacer or $300 for a spacer? that's how wild the differences can be and you better believe there is people who will tell you to pony up for the gold plated ones. Never cared to check why lol. All i know is that i did pay more than $100 for a set of DAMN spacers. Never felt more violated before considering i paid that much for silly ******** **** spacers. you can tell how much i'm fascinated for the POS considering what they do.
So no vendors list specifics in their websites, Tuff truck for example will tell you their spring rates if you call, Icon won't release anything about theirs.
So this is what we know and i have added to my list.
4th gen RAM 1500
rear coil spring rate i know so far:
The TT 1210 springs are 258 lbs/inc and they're supposed to be 25% extra load.
If we trust their numbers, then the stockers should be around 206 lbs/inc
TT 1210: 258 lbs/inch
TT 1211: 319 lbs/inch
TT1223V: 280 lbs (after the first 2" of compression supposedly that's their 2nd rate)
All of the above is here
https://www.ramforum.com/threads/ttc-1211.151245/#post-2135285
BDS 3": 240lbs/inch
As for BDS i have emails from them indicating free length and spring rates on their 3" spring. i'd guess their 5" spring is also 240lbs/inch, but 2" taller.
According to this sheet, a stock crew cab weights 2246lbs in the back more or less.
Suppose the factory spring rate is 206 lbs/inch.
the free length on the crew cab 1500 rear coil is 18.25"
that means you'll need 412lbs combined to push them down 1"
2246/412=5.45"inch of sag on the factory ones, meaning they should seat then at around 12.8" under factory rear weight more or less, add 400lbs extra weight to them and now they sag an extra inch and so for.