I heard that the HD put a bigger rear sprocket on the 09 models then they put on the 07-08 models . Is this because they put a bigger tire on the 09 models or was it to improve low end tourqe ??? Will the bigger sprocket fit the 07-08 models without a belt change ? What I heard was that the 07-08 models lacked power @ take off & the MOCO tried to correct the problem with a bigger rear sprocket . Is the info I am getting correct ?