there's some good advice in here, but i'd like to add some detail;
assuming you're on a budget
from 1979 to 1985 the toy front axle was the same>>>>. week spot - the birfield (cv)
running 33" or smaller tires, you'll probably never break one. don't run a spool up front, you'll hate it. use a "lunch box locker",,reasonably priced, simple to install, & quite durable. factory toy front has a lower axle tube truss, but i would do all the knuckle ball gussets.
toy factory rear axle; starting in 1986, was 3" wider and had bigger drum brakes, the v6 models also had larger carrier bearings(possibly the turbo 4 bangers also, but i'm not sure)
and no weak spots.
i've been running 37" military tires w/ double bead locks (lots of rotating mass) for quite some time, never twisted a rear axle shaft, never busted a lunch box locker, front or rear.
destroyed many birfields though
