I'm going to be building some bumpers for my 83, some questions first.
for the rear bumper, what size plating should I use for the recovery points? I'm planning on throwing 2 shackles along the back of the rear bumper in line with the frame. Also, what size shackles should I be using? I'll be doing this within the month when I get some more access at school.

 

I would go with 1/4". I built some steps that can hold the weight of the truck, but it has 3/16" plating around the 16 gauge 1.5" tubing so it has a lot of support and it still flexes. So a 1/4" plate with a good design should suffice.