DOTMAN- yes i run the stock belts. have only moved my adjusted back one notch and they are loose for MOD.
I break in all my bearing and belts for a good 3 to 4 hours with a silver can on the motor run in to ge the bearing and belts good and Seated and free everything up.
I have also not had any problem witht he EXCEL low Fric. belts. but only run them in Stock and 19t.