Swapped steer column, now won't stay running. Starts won't run.

The problem is your key cylinder has a specific resistance code that tells the BCM the correct method of starting is being done. I'm sure your security light is flashing. If you can try to use the original ignition cylinder. Or you'll have to have the truck programmed to the new cylinder

I agree with answer # 1... You need to swap the ignition lock cylinder so you can still use the original key to start the engine and for ALL locks!!