I suspect my company swapped engines. Is it possible?

Take it to someone who knows what they are doing. It should be easy to tell if the engine was changed, Nobody I know could change an engine without leaving any marks.

 

Why would you switch a good ecm for another good ecm? truck is running ok right?

 

I am suspecting luncheon meat.

 

Good question.
Possibly to show some different info for warranty purposes? maybe

 

Maybe the idle was too high and it would void the warranty before the "other" owners time was up? "preventative maintenance"?

 

Well, I do know that when I had my own trucks, I knew every little oil seep, every water mark, every mismatched gasket, hose clamp position, etc., on the engine because I opened the hood a minimum of once per day and did a thorough pre-trip.

 

Check the ecm mileage against your truck mileage. Easy to tell if it was swapped and your dealer knows it.