Here's what I've done to this thing so far:
Front Differential
We got an excellent deal on the 4Runner, and it soon became apparent why. The front differential was almost completely seized when 4WD was engaged. This explains the bald front tires I suppose? The previous owner(s) had installed a factory e-locker rear end in it, putting the gear ratio in the rear at 4.30. I never had a chance to verify, but I'm certain that the front differential was probably never swapped to match the rear. I picked up a used front differential with 4.30 gears out of a limited 4Runner and swapped it out shortly after purchasing. Look at how freaking burned the old diff is!! It's like there was zero oil in it!
Passenger wheel bearing/seals
After the front differential was replaced, it became apparent that the passenger rear axle wheel bearing was destroyed. There was clunking and grinding coming from the axle. After I pulled the brakes off, I found this lovely note scribbled on the rear axle hub. Remember how I said that I had figured out the rear's gear ratio was 4.30, so that's the front diff ratio that I ordered and installed? I about had a heart attack when I saw this:
I did yet another spin test to be sure I hadn't screwed up. The front and rear aren't mismatched! The junkyard just mislabeled the rear axle. Lol.
Shameless plug for my old ZHP that I will always miss dearly...
Tacoma front bumper
The truck was in a minor front-end accident before we bought it, causing the front bumper and core support to bend inward. We replaced the front bumper with my buddy's old Tacoma bumper that he wasn't using. It doesn't fit perfectly, but you can't beat free-ninety-nine!
Klever AT's
After getting basic driveability issues taken care of, I decided to put some shorter Kenda Klever 265/70/17 A/T's on. My wife and I were still both poor starving college students at the time and it didn't make sense to put another set of 33's on it... yet.
Steering Rack
After installing the tires, Point S told us that the steering rack was shot and they weren't able to do an alignment. I promptly ordered a remanufactured rack with inner/outer tie rod ends from Amazon and was really pleased with them. The truck aligned just fine after that.
Muffler
Replaced the old buzzy muffler at a local exhaust shop.
Cosmetics
We touched up the P.O.'s attempt to do a bed-liner section on the lower part of the doors. Prep work is key, people!
Rear hatch relay
The rear hatch on this truck was definitely replaced before we had it. The rear window, wiper, and defroster didn't work. When I tore the rear door apart, I found that a 99+ control box was in it, and the grounding plug for all the wires was missing! After some research, I found that I needed an older-style window relay/computer for my model of Runner. I ordered one from eBay and found a grounding plug from a junkyard. All rear window functionality was restored!
Knock Sensors and Valve Cover Gaskets
We got a check engine light for bad knock sensors. Ordered the OEM replacements from Toyota, got some Fel-Pro valve cover and intake gaskets, and swapped everything out.
Timing Belt
In an effort to keep ahead on maintenance, I went ahead and replaced the timing belt, water pump, thermostat, and pulleys. We had no idea if this had been done by the previous owner, so it was good to get this out of the way.
A/C System
During the timing belt job, I discovered that the A/C pulley has been flopping around. This past weekend I was finally able to replace the compressor, condenser, drier, evaporator core, and expansion valve. I had a local shop do the initial evacuation/reclamation of refrigerant (there were no leaks, just a noisy compressor.) I recharged the system myself. Vacuum pumps are life-savers!
I used this as an opportunity to try and straighten out the core support. I rented a slide hammer from the parts store and was able to pull the core support slightly. The frame crossbar is still pretty messed up. I think I'll end up having a pro body shop address this in the future.
There is still a lot on my list of maintenance to catch up on. I just graduated from school this May, and this truck has been in fairly rough shape since we've owned it.
Maintenance:
- T-Case seals
- Rear main seal
- Oil pan gasket
- Lower ball joints and other suspension pieces
- Vacuum pump ticking noise. Need to diagnose.
- Lower core support needs replacement
- Rear e-locker won't engage sometimes. Need to diagnose.
Mod plans:
- Retrofit headlights with projectors and some ricey LED's
- OME springs
- Bilstien shocks
- Less fugly 16" wheels
- 33" BFG A/T's
- New carpet
- Leather seats from a Limited 4Runner
- Tube/plate front bumper
- Toyota FJ-style grill
- Aftermarket roof rack of some sort w/some good LED lights
- Replace the fighter-jet style e-locker switch with something a little more OEM looking
/rant 
