Food for thought: I kinda had to go the OTHER way of all of this on my truck with a 4.10 posi.
2006, 4L60E, Z71 + 3in lift, 4.10 posi, no anti-sway bars, mud tires.
I had done all my transmission shift tuning on street tires with police interceptor anti-sway bars on a Z71 suspension. Retuning...