So I'm fairly sure my rear brakes are shot.  I knew they were thin but I drive all my vehicles like a stick so I tend not to use my brakes until I'm actually stopping.  They last me a long time, what can I say.
All of a sudden there's not much rear braking going on and my foot moves quite a bit more before I really feel the brakes grab.  Reminds me of when we regeared it and the rear brakes took a few days to finally seat in right.

At any rate, what size are the rear brakes?  Some sites just list by 2 door vs 4 door and others list sizes...which I'd bet means the 2 doors get the smaller brakes?  Anyone know the dimensions?

Thinking about getting a parts kit as well since the truck has about 180k on it.  Anything else I should pick up while I'm at it?

2 doors have the smaller rear drums. I think mine were 297mm but mine were Lucas/Grling so yours may well be slightly different.

All you really need are the shoes and spring kit. Unless your drums are bad, or you have a leaky wheel cylinder... but you won't know that till you get them off.

Sounds like you have worn the shoes down until they actually are not close to the drums anymore.  This would explain how the pedal does not "feel" contact for a while as you push on it.

You might check your front pads while you are at it...  Also check the slide pins on the front calipers.  One o mine "fell out"  causing braking to be a bit spongy.  I reinstalled new ones with Locktite and things felt a lot better.

I "engine brake" a lot on the Hypnotoad too.  The only bad thing about that its that it confuses all the "Amateurs" driving behind me...

"How can a vehicle slow down without putting on the brakes??"