After installing a remanufactured 4.2, the starter does not turn the flywheel?

You could have the wrong or a bad starter motor, can you see if the starter is getting power when the ignition key is turned to the crank position?

This guide can help:

https://www.2carpros.com/articles/starter-not-working-repair

Here is how to remove the starter in the diagrams below to see what's going on, also if you could upload a short video of the noise and what's going on it would help me see how to fix it. Check out the diagrams (below). Please let us know what you find. Also, it shows a ground cable going to the body of the starter did you reinstall it? Please follow the wiring on the starter solenoid as well.

Yes, the starter is getting power when the key is turned on. Another thing is it's the same flywheel and starter I had on the previous motor.

Can you upload a quick video of what the starter is going? Can you hear the starter motor run but it doesn't crank the engine over? I would try a new starter.