The numbers on the package indicate that the tachometer can be set to either 5, 6, or 10 pulses. Your engine emits 6 pulses so therefore it should be compatable, operating without any modifications.
Thanks Joe, Have had a hard time finding a tacho is Aus under $200. So maybe I'll save some money for a change and not have to get parts from the USA. I appreciate all the help, I am learning and this site is a great source of info.Keep up the good work