Engine performance

I am wondering if there is any way to get the exact engine specs on my 03 convertible mustang by a vin number. I bought it used and I know its a GT but I am pretty sure the Cobra Trim and tail-fin are aftermarket but I don't know for sure

It's pretty easy to tell if you have a real cobra or not. The Cobra engine is DOHC and has a big supercharger on top of it. The GT engine is SOHC and doesn't have a supercharger. The Cobra also has an independent rear suspension and the GT has a solid rear axle.