i would just buy a long chain that you know will go on and take links out of it untile it fits. but im sure there is an easyer way. it might even tell you when you get your swingarm
Easy way to do it is take a tape measure and hold it on your chain and see how many pins are in the 2 inch span, then add that to your stock pin number. Im guessing with a plus 2 you will at like 102 or 103.