Sumosprings

Have you researched other alternatives other than what you are using ?
I'm not saying it's bad, I'm curious as to why you have chosen those aftermarket springs. You might know more about this than I do. :) Read the links below for info.

I do not know if the TL Stableloads will fit your rig or not, but I installed them on my top heavy truck camper and they kicked in my overload leaf spring greatly improving the side to side body roll.

On my class c that I have now, I was getting pushed around by crosswinds and passing trucks, I installed a rear track bar and that plus a good positive caster alignment helped a lot. I also changed to Bilstein shocks up front and Koni FSD's in the rear.
At this point I'm at now, I can lead the pack through the twisties on back roads.
I will install more H.D. sway bars front and rear when the time comes, but for now, I'm happy.


I would take it to a scale and weigh get weights on each side. Your rig could also have too much weight on one side , then a set of air bags with individual bad adjustments to make it ride level from side to side would help.


https://www.torklift.com/rv/stableload

http://www.ardentcamper.com/blog/steady-as-she-goes-stabilization-and-safety-upgrades-for-class-a-gas-rvs

If you want to reduce body roll, you want stiffer sway bars. Usually you'll only want more spring if you're hitting the bump stops too often.

you want stiffer sway bars.

Yes, on my previous camper I did the sway bars first, then later on I still had more roll than I would like.
After speaking to the TL people for advice, I installed the Stableloads, which are adjustable and helped with body roll even more. If someone was experiencing a lot of roll, they might benefit from using both.
I'm just mentioning the SL's as an option that's on the market. BTW, the TL company is very professional and they back their products .
If I felt I had this 'body roll' issue on my class C that I now drive, as long as they would fit my application, I think I would try the sway bars first again only because IMO, the OEM SB's are a little thin and I plan to swap them anyway, once I accumulate some more miles.
However, it would be interesting to see if the SL's alone might have been the better bang for the buck . I don't know because I never tried installing the SL's first.

Stableloads….. (If someone felt they needed more spring )They swivel on/off...to engage the overload spring or not. On an 'as needed basis' which turned to be 'always needed' :B
When engaged they will make the springs more stiff. On an empty truck with less payload, it would be a harder ride because the overload would be making contact, which would be like adding an additional leaf to the spring pack and that helps with body roll.

Another option if your rig is always maxed out, is to go to a spring shop and add a leaf to the pack, I have done that too for $500.

Two answers to your question:

Will auxiliary springs with stiffer spring rate reduce roll/sway? YES.

BUT, (yes, big BUT) they will also stiffen the ride/make it ride harsher.

As already posted, if roll/sway is the problem, not bottoming out, then stiffer sway bar bushings and/or larger diameter sway bar will reduce roll/sway without materially stiffening the ride.

wolfe10, thank you for making that more clear, you're right it absolutely did make a harsher ride. I would not use the SL's unless I was running at a max gross situation as I was.
My rig didn't feel so hard at max. It didn't pound like it did running light, that was too hard a ride. That was the nice part of the adjustable SL's , it allowed the normal OEM spring rate when not needed. Just swing the SL's out of the way as I did. I think there are two models of SL's stationary and adjustable. I would only install the latter.

I wonder if the OP's floorplan has a drivers side full slide, making the rig off balance to begin with ? like the 31G.
If that's the case, then maybe a set of air bags with individual lines to level it side to side would offer a better fix.
I would get a scaled weight to see how close you are to gross weight all loaded up as well as right to left weights.