Here is my own 09 SG, bike is being bumped to a 120 at the present time , but this is what it had . 107 kit RR cast HP heads crane cam, zilla pipe and a 58 t/b. I love to here the key board engine builders state that the use of a zilla or a 58 on small engines will kill low end power. We did back to back testing from a bored FBW to the 58 and a fat cat to the zilla. It only got better with the larger items. BTW the other is another we built that is a twin engine wise to mine. Power wise extremely close.