I was wondering what belt size to use with an aftermarket under drive pulley. not sure what brand is the pulley, but the belt i have on now is kind of too short. I tried numerous belt but can't get the right one. does anyone have an idea what size to use....??

 

Have you tried contacting gates?They may have what you are looking for.

 

You might get lucky at a local auto parts store, if you take the belt in they can find the next size bigger for you