Further info: This high-pitched noise started occasionally on ignition, then soon started to come on under load. Now it's constant until engine warms up, then disappears until revs exceed 2000 or so. It changes pitch with engine RPM. Maybe 200 miles run since repairs and onset of noise. AC compressor is fitted but not the problem.

My questions: Could a crank bearing go bad so quickly, and would it be really loud like this? If yes, am I trashing the bottom end by continuing to drive the car? Could it be the crank pulley itself? Would that tilted alternator have so quickly screwed up the shaft or impeller of the water pump? Is it possible internal lube of water pump deteriorated in years on the shelf? Could it be something else horrible, like the timing chain? THese are the questions that keep me awake at night.

Please post or email your comments and theories, expert or crackpot welcome. TIA