I've heard of a few guys who just swapped computers without any dealer flashing/vin programming, etc, and the truck would run fine.
maybe they were non-security trucks, I don't know.
if your truck does not have the security package on it, then maybe you can get by with a junkyard PCM, just to troubleshoot.
find one out of a truck that was clearly running and driving all the way to the scene of the crash
![](/ubbthreads/images/graemlins/hammer.gif)
use it to troubleshoot, and if the truck starts right up, then you know it was the PCM. if your junkyard piece fails quickly, then invest money on a more expensive reman'd unit with some sort of a warranty.