Engine Numbers what do they mean
 

I am trying to figure out what motor fits my bike I have a 2000 GSX R600.I am told that only a 99-00 engine will fit and work with no modification.I have a lead on a motor but the gentlemen is unsure of the year. I am wondering if there isway to tellby the engine numbers the year. Any advice at all will be greatly appreciated.The Number is N714-139561