Can't speak to which belt to put in. One thing I do know, these belts to not cotton to picking up rocks. If you pick up a rock, neat the outside edge, you can make a spit that will let go when you twist it. Get a bit enough one and it will go right them. That is the reason I stay off of dirt and gravel roads, other than having to spend hours polishing, that is.
Enjoy,
Rich P