I have a 2016 1200s. gotta make a bit more research thenYou are all good to go if you have a 1260.
The 1260 stock chain is 114. Consequently, a 120 links is the safe way to go but you'll need to shorten it.
However, the stock chain on a 1200 is 108. Thus I believe a 110 links will suffice to fit a 42T sprocket.
Other 1200 riders should chime-in to confirm.
thanks man !