It sounds like the Icon springs might be my best bet, since my truck doesn't have the off-road package. As long as the spring rate works with the 5160s, they should get me pretty close to what I'm looking for.
I do have about 400-500 lbs of weight (shell, drawers, tools, etc.) in the bed all the time, and I'm looking for better washboard/forest road performance overall. Folks generally seem happy with the Icon springs.
I had the Icons 1.5" before the Claytons 2.5" Both seem close in terms of the weight they can support. They're progressive so their spring rate varies with weight. you can't exactly predict how much sag you'll have like you can with linear but as opposed to linear rates, Icon have a much heavier rate than stock when pushed down with load. We don't know how much they need to sag before reaching out that load rate though. We have guys doing verifications around (Thanks to everybody adding weight in the back to test and measuring with ORP, Clayton etc
so if you get Icons in your non-ORP truck it'll be interesting to see your lift height, and if you can do a measurement with 300 and 500lbs of weight in your bed, you guys will have a nice reference point with 3 different springs.
Those Icons will work nicely with 400-500lbs of weight, keep in mind they'll sag around 1" overtime with that weight. So you'll be back to whatever you have now with your factory non-ORP springs or 0.5" higher at the most. Again I haven't been able to confirm how much height you'll gain with them in the DT trucks but given the consistency i've seen with Claytons and what i had with Icons before i'm confident if you keep your front at 2" lift, the back should look level with the Icons and 400-500lbs of bed weight. all this only for Non-ORP equipped DT trucks.
Icons are 19.5" long progressive rate (You can run up to 27" maybe 27.5" extended shocks before you can unseat them, heavier spring rate should be 360lbs/inch)
ORP are 20.5" linear
Eibach E30-27-011-02-02 are 20.5" linear
Claytons are 21.5" progressive (you can run 29" maybe 30" extended shocks before you can unseat them, Heavier spring rate is 360lbs/inch)
Hope it helps.