Was able to go through the 2016 RZR microfiche and below is what I can find so far and please no one hold my feet to the fire, the microfiche is not 100 always.

2016 XP1000 and XP4 1000 no change in clutching that I can see. The XP 1000 is actually not on the microfiche but the XP4 1000 is I am assuming no change for the XP 2 seat. Same belt as last year

1000 S model, all new secondary clutch not seen before with square secondary rollers called square tied pucks on the outside of clutch and still round ones on the helix on inside, same primary clutch and belt as the 1000 XP

900S model, same everything

1000 Turbo, all new everything, belt, primary and secondary. Will it work on a XP? No idea, even if physically fits, the springs weights etc would not match the XP model

This is what I have so far, I will edit this and update it as I know more.

Todd