With your curb weight at a stated 7000lbs giver take a hundred, 4300 lbs total payload on the truck is plenty to keep it planted. Plenty.
Considering you claim to have some weight transferred to the front axle, it should feel very planted.
Considering you’re planning on front Sumos you must feel the front is loaded heavy (sagging, squishy) which I doubt. But front sumos, if it’s sagging enough to engage them, will make the front stiffer.
Or in other words, the condition I think you’re describing is not commensurate with the solution you’re proposing.
