I can find out this week, I have my RC8 in bits so can try Slipper in my 4x4 once I have them together.
You'd probs have to cut the driveshaft I imagine?
EDIT: Just had a look, don't have Slipper at hand but know roughly how big it is. There is a lip on the top end of Slash chassis which the Slipperential will probably hit. :( There isn't much room length ways.