Odb2 not responding to scanners no start diesel plus it only tries to turn over in neutral?

Okay, if the replacement engine is a 03 it shouldn't be compatibility. I didn't see any tach bounce while you were cranking it. When you turn the key on do the gauges do anything?
If not, then I suspect we are going to need to verify the powers and grounds to the ECU and the dash as a starting point.
Attached are the powers and grounds that feed the ECU. I would check the fusible link that feeds the power to it and make sure it is there.

I would first check the fuse #51 in the TIPM for power in the left rear of the engine compartment.

This guide will show you how:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If there is no power, I would replace the TIPM which is easy to do because it-self learns. Here is how that is done in the images below. Please let us know what happens.

I have also seen the cluster cause this issue as well. Can you please check the fuse #51 for power?

It’s very hard to get air out of diesel system I’ve found cracking 1, 3, 4 injector fuel lines then cranking it (will probably take several times) but eventually does the job then once it starts you can bleed each line out while running to push air out then tighten. Unfortunately, there is no fast easy way of doing it that takes a little time.