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Wavetrac <= clickable. They have the most impressive of the torque biasing differentials available. They also have the strongest with 12 pinions vs six or eight in the other manufacturers diffs.
In addition to being very strong, they dynamically bias the wheel torque with their patented wavetrac mechanism without preloading the diffs internals like all other designs. Your car will feel much more neutral going through the turns with this style of differential. Very impressive unit not a very inexpensive unit.
Ed
p.s. They make a 31 spline 8.8 IRS version and a 31 or 33 spline 8.8 straight rear axle version and all versions carry a lifetime warrantee even if you race them!