Alright, I know it's an odd topic, but here it goes. I know that most USDM Engines have a serial number that starts with a 1, then # # # # #.... and so on. I'd go out and look at my motor right now, to see the exact number, unfortunatly I'm wearing boxers and that's it, and it's -5° outside here in Denver right now. So no exact numbers. Well, I recently bought a stock engine to use in this cold CO winter-- it's been in the car for a couple months now, but the serial number starts with a 2. What's the significance of that one? Anyboyd??

 

Any insight here???