Toyota aftermarket upgrades:
Chromoly 30 spline super birfields and axle shafts.
They eliminate the neck down on the shaft as well
Billet Hi steer arms
Or Forged Steering arms
Factory Electric locker and Hi pinion diff:
Offered on landcruisers (fj80) are Front Hi pinion diffs
Also available is the toyota Hi pinion Electric locker
Standard Low pinion Electric lockers were available with the TRD options on Tacoma's and 4runners.