I have a Polaris 500ho RSE 2002. I was looking for u joints and found that a spicer 5-170x u joint fits the center driveshaft and I would also guess all the u joints on the quad, bonus they are cheaper than napa , at least here.
Napa 338. $25 bucks plus tax but not in stock
Spicer 5-170x $16 dollars plus tax
available at most truck shops that install power take offs and such and they are greaseable
Don