Add more leafs to the rear springs inthe front, and it will handle better. Also leave the overloadsin the chevy springs, and it will really reduce body roll on the street and help keep the tires out of the fenders.
I can cruse at 80+ in my 4runner, and it is dead stable with my 83/84 yota rear spring hybrid pack. I did the math, and figure I got about 3" of lift out of my spring setup when I put it on, and after wheeling it a few times, about 2.25".