Just the rear Super 35. A Super 30 converts the front shafts from carbon steel 27 spline shafts to 4340 chromoly 30 spline shafts which would be overkill. For a front locker you only need replacement 4340 chromoly 27 spline shafts for the front which are not that expensive. That way you can stay with the OE 27 spline unit hub bearings too.
