[D13]

The JB5 uses the thick rotor (1-1/4" and appropriate spindle and dust shield. I recommend measuring your rotor as many of these trucks have had part swaps over the years.
In the rear you need bigger drums and backing plates. Often easier to get a whole rear and swap.
Master cylinder is different too.
They really don't change the braking much on an unloaded truck, will lock the rear up a little quicker. Real change is when loaded and under repeated braking.