I just put a 520 O-Ring chain on mine. Because of the extra chain width, you'll have to remove the chain guard, since one the lower bolts holes for the rear support rubbed on my chain. But, since, I have changed to FUTV's new swingarm and it's a non issue, there's no chain guard for this new component.
the pins in the links it just depends on how you order chain. I order a 160 pin chain a year but that is about the same number of links. Start at the master link and go around till you bet back where you started