[snshddog]

The first thing to say is wow, I have never heard of that before. That said, it will help if you have info on the engine that was put in. With luck on your past bill it will have the serial number of the new engine. If it doesnt then check with who put the crate engine in to see if they have that info. You have to be able to prove that this guy was given the car with a different engine.