make the rear camberlinks long.
raise the rear ballstuds at least 3 mm to get the rollcenter down
I would go with 5K rear diff and around 7 or 10k front diff, depending on surface and layout.
2mm front swaybar
long wheelbase
stiffer spring in the front.

these are the thing I have done to get the rear to react a little slower and make the rear more stable.

Im not finnished yet, couse when I push harder on the truck , the rear is still easy to come around.
but Im getting there