AFewScrewsLoose

Howdy folks. Name's Derek. Lurked here for a couple years on and off, always had a thing for the old Yotas.
87 automatic trans 4WD, 22RE

Last Friday, put some smaller (stock size) wheels and tires on, those 31s felt slow as dog ass. Get home that night, doing 65 or so, truck is doing fine as usual. Get home, put it in park, notice a bit of a squealing sound (not the first time). I figured it was the PS belt, because it looks really cracked. Killed the truck and didn't sweat it.
Next day, go out to start it, truck takes more than a few cranks. Engine is noisier than usual. Some squealing sounds, but I'm not sure of much-I wrench on my own rides but I'm no mechanic. Thought I heard some clattering sound.
Listening to it idle, the motor starts to shake like it's misfiring. Some smoke starts coming out of SOMETHING under the hood and it gets worse. I started diagnosing-pulled plug wire #1, engine dies. Start it again. Smoking from somewhere under hood, but not out of exhaust?? Giving it some throttle, more smoke. Near as I can tell it's emanating from engine front, around crank pulley?

Feared the worst. Drained oil to check for metal pieces-none, and oil is not milky, looks perfectly fine. Coolant levels ok, never had to add any fluid, and no evidence of oil in coolant (I didn't drain that though).
Put fresh oil in. I ran a compression check- 120 to 150 psi on all cylinders. Not great but not terrible :/
Changed spark plugs and plug wires (damn cylinder #4, I cross threaded that one on a different truck a year ago).
I was still scared so I pulled the valve cover. Timing chain looks ok, guides are in place and undamaged, no excess slack. I didn't see anything unusual around the valve train except HOLY BALLS that is a lot of carbon buildup on the exhaust side.
Put it all back. Changed PCV valve and grommet.
And now....
It drives ok. Idles alright, sounds like a small misfire but I can't figure it out yet. No more smoke! When you take it out of Park or Neutral and into Drive or Reverse, the idle drops (like it should) but the whole truck starts to vibrate!! What's up with that? It goes away once you up the RPMs.
However, it can do 60 on the highway. I should also note, if you get on the gas hard, there is an intermittent high pitch whine sound. WTF? Still feels slower than before.
It's really a head scratcher, y'all, or I wouldn't be posting it here.
Any thoughts? Distributor jumped? Vacuum leaks R Us? Torque converter shudder? Help me Obi Wan...

AFewScrewsLoose

Hey guys, just wanted to update this instead of leaving it open. I was checking my vacuum lines (no leaks, woohoo) and I remembered that when I put them back on after pulling the valve cover, I wasn't sure about how the power steering idle up diaphragm (little canister behind the distributor with two lines connected) connected to the throttle body.

For those of you wondering, the line from before the throttle plate goes to the engine-rear-facing nozzle on the idle-up, and the other vacuum line connects the other idle-up nozzle and this little air valve with a spring and a screw on the right side of the throttle body. I believe this is to adjust idle speed for when the AC is running.

I don't know if I explain things very well...and I'm pretty wordy...but 'sall good