I've got a few more things to do before I can focus on cleaning...
I bought a Thrush Turbo muffler, 2.25" offset inlet, 2.25" offset outlet. After driving the truck in actual traffic, I'm wanting a little more muffler than I previously thought I wanted. And it was on sale at AutoZone. I'm going to just clamp it onto the exhaust and see how it sounds, and from there I'll decide whether I'm going to add more tubing myself, or just take the truck over to a shop and have them bend up some tubing and weld it in.
I need to bleed the brakes again, there's a load sensing proportioning valve connected to the rear axle that is supposed to increase brake pressure when there's a load in the bed... But this one has been neglected for who knows how long and of course new/rebuilt ones don't exist. It might be somewhat functional, considering that both front rotors show obvious signs that the calipers are clamping down on them. I don't know if the proportioning valve is holding pressure in the rear wheel cylinders, or if the pumping I'm doing is just pumping up the rear drums and I still only have manual brakes.
I have yet to actually "test" whether the brake booster is airtight or actually functional, but the tests for that are super simple, like turning the engine on while holding the brake and seeing if it moves, turning the engine off while holding the brake pedal and seeing if it drops within 30 seconds. I don't expect it to be fully functioning, but there's not much I can really do right now if it's not. :th_shrugshoulders:
I've also got a little bit more tuning to do. I adjusted the idle mixture to lean it out just a little because it smelled a bit rich, and I want to get a timing light on it to see exactly where it is. I had a small issue where it started running rough on start up, almost like it had a big vacuum leak. I got it to clear up by revving it to 2500 RPM, where it would instantly smooth out and jump a little in RPM before returning to a smooth idle. It hasn't been happening as often now, and part of me thinks it was the mechanical advance inside the distributor sticking a little. I'm considering pulling the distributor back out to clean and lubricate it, and I'm wanting to get a timing light on it because I'm mildly concerned that the distributor might be off by a tooth. When I was setting the timing by ear, I could advance it all the way and the engine wasn't missing as much as it should have been... Because the Weber carburetor pulls a lot more vacuum than the stock carburetor did, the vacuum advance on the distributor could be what's letting the truck run as well as it does. Plus, when I was setting the timing I didn't have a helper to hold the RPMs at 2k, so I used the idle speed screw to hold it and now I want to do it again the "right" way.
That and adjusting the idle mixture most likely changed the ported vacuum, which would throw off the timing as well.
Another weird issue, random fuses will pop at random times. I've had the reverse lamp fuse pop, the turn signal fuse, the radio fuse, the taillight fuse, and the fuse for the extra 12v outlets. The fuses for the lights might be because I had to cut the terrible attempt at trailer wiring out of the taillight harness, and there might still be some wires I missed that aren't properly isolated. I don't know why the radio fuse blew, or the outlet fuse, which was in a completely separate fuse block from everything else, and I don't have anything plugged into it...
But the dome light is working more often.

It used to be about every 10-15 times I opened one of the doors it would come on, recently it's been almost every time. At least there's one part of the truck that's self-healing...