Welcome to the site !!
From what i understand , they changed the swingarm mount location on the engine in 06 to tilt the engine down to lower the center of gravity , in doing so , the header was changed and the engine mounts themselves , so i do not believe it would be a "direct" bolt in , basically , the internals of the engine are the same with the exception of a change in cam profile , but the cases have different mounting locations ....hopefully Ken chimes in to confirm .... with that said , i would think if you had the motor mounts and the header from the 06 it should then work , as i believe the frame mounts for the engine are in the same location between the 2 years and only removable engine mounts and engine cases and header were changed ...