'76 C10 Crank Pulley wobble and squeal EQUALS?

[76C10Stepside]

This has been coming on for a long, long time. For years I thought it was just a squealing belt. Recently, the fan belt "disappeared" while driving it in town. I replaced the water pump and alternator, trying to cure the squealing, no luck. It got a lot worse the first couple of times I ran it, but now it's back to just squealing when I gun it. Needs new spark plugs real bad, so is running a bit rough. I have not driven it at all since replacing the water pump, just ran it in the driveway. It idles fine and is quiet.

I was thinking a galled/spun crankshaft bearing. Then I noticed that the crank pulley was wobbling slightly (never did that before). Found the crankshaft pulley bolts were not tight (the larger center bolt is tight, though).

After tightening the pulley bolts, the pulley and harmonic balancer both still wobble a little, and when I gun it, it squeals for a a second. I tightened up the alternator belt, but it still squeals.

It's NOT just the harmonic balancer that wobbles. Seems to be the crankshaft or the front bearing that is causing the wobble. Edit: Also, NO engine leaks at all, so seals are intact.

So, what's the verdict? Broken crankshaft? Failed or failing bearing? Should I risk driving it around town? My S10 is also down with a mystery electrical short that is probably wires in the steering column, which will take awhile to get to. Need groceries, please help! Happy Holidays!