Dana 80 Detroit TrueTrac, 35 Spline, and 37 Spline, 4.10 and Up carrier or 3.73 and Down. A very good limited slip, the clutchless design makes this an outstanding product that does not wear out. It also does not require special fluid. No clutches to burn, crack or spin. If your looking for more traction but need good road manners this is a great option.