I had a similar screeching sound at start up on one engine and it turned out to be starter alignment. But one look at the starter or flywheel confirmed it.

That starter is a mini high torque replacement, and has been in there for 4 years. After removal, the gear on the starter looked fine and the flywheel ok. I did see one shiny spot on the outside of the teeth of the fly wheel, but the teeth were okay. There's only 45 hours on these engines. Like previously said, it turns the engine over smoothly as long as the ignition coil is not connected..
I'm going to check the Ignition switch today. To make sure that when the key is on the run position the start wire is not getting power.

Another thought! Is it possible? My holley mechanical fuel pump mounted on the block could make that kind of noise. Standing by the dashboard that noise seems loud coming the front of the engine somewhere.

On where the sound is coming from, your ears and the environment around it can play funny tricks, but in general you would be right. If it's the drive, you should be able to tell with your ear close to it.

Starter alignment brings up a good point. It could be binding installed in the engine on the flywheel, but not on the bench.

I would think the fuel pump would make more of a "tick" than a "screech"

If your key switch is difficult to get at, you should be able to disconnect the yellow/red wire at the relay, and the jump the 2 posts to bypass the key switch (but with the key still in the "on" position) and run it.
dis regard if starter is still out

Doing that test later today I will get back to the group.

possible issues:
1 starter bendix is getting hung up on the ring gear, need to shim the starter down
2 starter bendix is getting hung up on the ring gear because the soileniod is sticking and not allowing the bendix to retract.
3 vacume leak- under carb, intake manifold
4 bearing screech.- rod or main bearings have no oil ( I had this happen to me even after I primed the engine)

Is the screech sound there even after the engine is started?

Also your timing seems to advanced, could be the engine is rocking backwards and causing the starter to spin the wrong way.

Keep us informed of what you find.

thanks the timing is a bit advanced due to swapping distributor. Timing locked out at 34. No advance.
oil left the pan during cranking. Showed lower on stick.
returned to full next day.. cranking engine no noise with coil dis connected.. What about gimble bearing.

My buddies Wellcraft Nova had this issue years ago, bravo equipped 454, it was the rubber coupler on the flywheel flexplate, pull the drive and see of the noise stays.

Okay, I did the Ignition switch test with power.. Connected battery power alternator and Ignition wires together. Just like it would be connected to the starter. Took a Volt meter at 12 VDC and measured from the start wire to ground. Relay activated on start, which is next to the 50 amp breaker.. yellow /red pin stripe start wire received 12 volts. Turn switch to run voltage dropped to 4.5 volts. Here's a point I don't know how old that starter relay switch is. But if that gets stuck with the contacts inside that could do the same thing as the Ignition switch. Keep the starter activated
For 30 bucks, easy to change..