Engine will not start

Does this truck have a tachometer? Is it registering anything during cranking? It ran fine up until changing out the clutch, where Dodge had you switch the flywheel and CKP sensor, correct? Do you have access to an O-scope? If yes connect it so you can see the signal from the crank sensor. Chrysler likes to change things at times, I am wondering if the "new" flywheel might have the wrong trigger sequence. They did that a few times over the years. You may be able to see the notches if you pull the crank sensor and use a bore scope. Count them and compare it to the old unit. A bad crank signal shuts down most of the engine controls to avoid damage.

He installed the new sensor and it stopped running. Did he try a second sensor? Would not be the first time a part was bad out of the box. Especially with the parts "quality" these days. That is a three wire sensor, it has a power feed to it, a ground and the signal. It is not uncommon for them to lose one of the circuits. You wrote that the circuit was tested and was K, was that just at the sensor connector or at the connection on the PCM itself? The sensor may be fine but the harness may have a bad connection.

Not connecting to the PCM is not a good thing. Unplug the crank sensor and see if it connects, a bad one can stop it from operating.

This is going on too long. Before you get more wrapped around the axle with confusion, stop everything and find a mechanic with a Chrysler DRB3 scanner. With an extra plug-in card, they will do emissions-related stuff on every brand of car sold in the U.S. Starting with 1996 models, so a lot of independent shops bought them. The dealer will have a couple of them too, but they started becoming obsolete on a few 2004 models, and all models by 2009, so the dealer's will be packed away. I have my own to use on all of my vehicles.

This scanner lists the crankshaft position sensor and the camshaft position sensor under the "Inputs/Outputs" menu with a "No" or "Present" during cranking to denote whether their signals are showing up at the Engine Computer. At this point we are all assuming the cause of the no-start is the crank sensor, and no other tests have been done. This scanner also has a "No Start" menu that lists the exact reason the Engine Computer is unhappy and it will verify the automatic shutdown, (ASD) relay is not being turned on. If you should find the ASD relay is being turned on during cranking, that would prove the crank sensor is working and we have to look at the other possible causes of the no start.

A lot of independent shops are now using one of Snapon's scanners for newer vehicles. I bought one of those for my newer truck, but I have not bought the adapter cables for my older vehicles yet, so I do not know if that will show those two sensors or how their status during cranking is displayed. I am recommending the DRB3 for this because I know how it works for this type of problem.

Not surprising, many independent shops use third party test equipment if they do not do a lot of one particular make simply because of the cost of buying each specific tool.
As I said, if it is the wrong or shorted sensor and it cannot connect to the PCM, unplug the crankshaft sensor, as a bad one will stop the PCM from communicating. If you can now connect then there is either something wrong in the wiring harness or the sensor itself.

Maybe go and get a cheap code reader or have him try a different scan tool and see it it will communicate. If neither one will and they work on other vehicles then it is time to work backwards. If the only parts changed were the flywheel and crank sensor and now it does not run, it is either they are not correct for that engine or there is an issue in the sensor or wiring. Or there is a problem with one of the other sensors that they needed to move when pulling the transmission. Like an O2 sensor harness shorted or a ground not attached.
Something that is easy to overlook when you get frustrated.

We are missing something here, does the engine have compression? if so spark and you can hear the fuel pump in the tank prime for five seconds?

Has Mr Compo tested the wiring harness for connection power and ground. If not I think that.

https://www.2carpros.com/articles/how-to-check-wiring

Has the ASD relay been checked?

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the diagrams (below). Please let us know what you find.

Cheers, Ken

The only real way to test this is going to be to put a scope on it and see what signal the flywheel/sensor combination is sending, if any. An older analog voltmeter might show the activation of the sensor if he connect the leads to ground and taps into the sensor signal feed to the ECM. Then with power on but disconnect fuel and ignition and bar the engine over. There should be pulses in the same order as the old flywheel. 1-2-1-2-1-2 etc.
If you are getting those pulses at the ECM connector the problem is not the flywheel or sensor. Another item to check would be to put a piece of clay/gum/poster tack on the end of the sensor, dab a bit of oil on the end and place it in the hole to make sure the sensor air gap and flywheel tone ring are in the correct location. If the gap it excessive you get no signal or if the ring is not in position you get no signal.