Not sure if I can add any valuable information to help you with your decision, but I will try:
Tuff Country advertises their HD springs as being adequate for trucks with big block motors OR heavy duty winch bumpers. They will tell you that these springs will not provide the specified lift height if you have more weight than either a big block, or heavy bumper up front.
During my recent Dana 60 front axle swap in my 3/4 ton suburban, I decided to install a set of 2" Tuff Country HD springs in place of the slap-worn-out (negatively arched) stock springs in the front of my truck. My suburban has a big block, a big heavy front bumper that doubles as an air tank, a belt-driven air compressor, a winch, and 2 batteries (and now a Dana 60
).
After reading their disclaimer (which I summarized above) I was concerned that these springs wouldn't hold up to the weight in the front of my truck. In talking to a Tuff Country tech rep, they told me that the spring rate is not great enough to maintain the advertised lift with that amount of weight, but that there would not be any real functional/performance issues with the springs. That was good enough for me, because I wasn't really looking to add any lift, just wanted to get the tired springs out.
It is hard for me to say exactly how much lift the springs gave me after the swap, because the axle itself is bigger, and the spring perches are taller. But the new springs are not flat - they do have some amount of arch to them. All in all, using my calibrated eyeball measurement, I would guesstimate that the front of my truck is now somewhere between 3"-4" taller than it was before the axle and spring swap. And I would guess that about 2" of that is related to the axle size and spring perch height. Which means that the springs did still give me somewhere between 1 and 2 inches of lift, even with all that extra weight up front.
Sorry for the novel. Hope that helps.