All of this work is finally wrapped up as of Friday (Jan 15, 2021). Denso remanufactured starter installed, new lower intake manifold (pulled from a 4.7L Sequoia, VIN: 5TDZT34A13S164720) installed, injector seals replaced, throttle body cleaned, and everything buttoned back up.
Getting to the starter wasn't as bad as I'd read. The biggest PITA (new to the lingo, still thinking about hummus) was making sure I had all the nuts and bolts organized. For the intake manifold, I followed the SOP from other part installs, finding a piece of cardboard or a box, shoved the taken-off bolts through it in spots corresponding to where they came off the manifold. Nuts... I laid them out on a shelf in my garage, similarly to how the bolts were organized, corresponding to their installed locations.
I made the mistake of having all the manifold AND valve cover/coil bolts out at the same time, which led to more bolts needing organizing than was necessary. Had a bunch of them tossed in a magnetic tray by the time everything was disassembled, which didn't make things any easier. Got a little excited once I'd gotten the new starter in, and started throwing those bolts into vacant holes before thinking things through, so took them all back out, slowed down, followed FSM etcetera, etcetera, etcetera. Sorted.
The old non-OEM starter was in decent shape, but obviously had very old contacts in it. One was much smaller than the normal starter contacts (like slightly probably 1cm x 1cm in area), and one was much larger (basically crammed in the damn thing). The larger one was worn down wafer thin, and the pluger wasn't in great shape. Got the Denso off Amazon, with no core charge, so I think I'll "rebuild" the old one, and hang onto it in case of emergency down the road. Plan might change.
The new starter looks beautiful in place. To be honest, after climbing into the engine bay as a 6' 4" 205lb man and fishing the bolts out of the back of the starter, the hardest part of the process was accessing the bolt that fixes the battery cable to the starter. Required a bit of a twist and pull/twist and push configuration while removing/installing the starters. Good opportunity to remove what I could only describe as being an owls living room, from the cavity between block and intake manifold.
A note worth making, given the photo above... I did all this with the fuel rails left in the engine bay, as opposed to pulling them with the intake manifold. This was NOT the move. I had to undo one of the fuel lines (mitigated spillage with mild success) to get the intake manifold to clear the rails on removal, so I would have been well served to just undo the other one as well, and pull the entire assembly. Would also have made injector seals access more convenient.
Fired the truck up. Started stronger, ran way smoother than before all this work, which was encouraging... until I realized there was probably a quart of fuel on the floor of the garage whilst I hooted and hollered at my great achievement. Feared a cracked fuel rail, but upon further inspection, I'd seated one of the injectors slightly off-kilter. Adjusted that, fired it up again, and all was squared away.
Bled brakes, bled AHC... both had some RIGHTEOUS grime in them, so good to get those addressed.
Next on the list as far as priority goes:
1- Replace broken lug nut so that the thing passes inspection once I've got the title in hand.
2- HOSES! Bunch of the air lines are cracking at their connections. Fuel and fluid lines look to be in much better shape though, far and away.
3- Thermostat. I left the truck idling for probably 30 minutes, and the temp started climbing. Drove a lap around the block, let it sit, and temp continued to rise. Let it cool off, fired it up again, and held steady at idle. Assuming that idle was under the 180 degrees required by the thermostat to open, and that driving got it above that threshold while thermostat remained closed.
4- Ball joints/LCA bushings/reboot CV axles. It's a nightmare down there, and that will be the real work. I don't have a press or tools for that though, so I may have to do the ball joints and bushings with a local shop, unless I find a good work-around.
5- Diff/T-Case fluids, ATF, tranny. All drain and fill. Bottom of the list because I won't be putting much in the way of miles on the truck until thes above are addressed.
Otherwise... I've ordered the Gamiviti Roof Channel Towers, in anticipation of building my own roof rack. Get the ROAM toof-top tent on there while I finish the trailer, and we'll be off to the races, hauling this girl on some new adventures.