I re welded all of the factory welds, as well as the seams. Added a some metal around the control arm mounts and the the steering box mount. I put some holes in the steering box gussets as not to trap moisture. As you weld, lots of compressed air to keep it cool so it doesn't twist.
EDIT: Beware when you weld around the control arm mounting hole. Your welds, and the support metal needs to be below the shoulder of the mounting hole or the control arm will not be seated properly when tightened down.