The slipperential fits the xt8 and xb8 directly without any mods - you will need to add about 3mm spacing underneath the center diff assembly for the 808, though.
Yea I think I need one of these I snapped my front center cv joint on my XT8.Best of all it drops in.No shims or mod required.
SC8-E RCM MMM CC 1717
Slash 4x4 MMP CC SC 2400
SC RC8BE MMP Neu Tekno 1512/2D
Mugen MBX6 Eco MMP Neu Tekno 1515/1.5D