Truck in question does crank, but it does not start?

Hello,

You will need spark, fuel and compression to start the engine.
Have you got a chance to check for spark and fuel?

You can check for fuel pressure.
You should have 55-62 PSI of pressure with key on and engine off.

https://www.2carpros.com/articles/how-a-fuel-pump-works
https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Last item would be check for cylinder compression.
Low compression will keep the engine from starting even with spark and fuel.

Here are few helpful articles:

https://www.2carpros.com/articles/the-reasons-for-low-compression
https://www.2carpros.com/articles/symptoms-of-low-compression
https://www.2carpros.com/articles/how-to-test-engine-compression

I have attached diagrams for your reference.

Please let me know of any questions.

Thank you.