engine identification

[lastplacex]

I have a 2005/2006 Yamaha R6 or R6S engine with the bells and whistles. Is there anyway to distinguish these engines from outside appearance? I have just about everything from header to tach to even the kick stand. If I am not mistaken, I know that the 2006 R6s has the long muffler, which is the one I have. I know also that the 2005 R6 has the long muffler also. Moreover, do these engines have the same technical aspects as of mechanicals? I realize that they all have different strokexbore combos and some other small stuff. Anything will be useful. Thanks for everyone's time.