Another option to consider along the lines of that slipperential is the
TEKNO Traktion Drive Kit , this will make the car accelerate more like a nitro so you can mash the throttle hard and put far less stress on the center diff, be sure to select the
right size clutch bell to replace your pinion toward the bottom of the page.
*** EDIT, I see I just got ninja'd, while looking up links, ha!