Should be ok, you may need to change the speedos over as I haven't got a clue if there's any gearing differences between the drives for 899 and 1108 - but they used to sell an 899cc SX with a rev counter etc. so all the wiring should be there somewhere.
Pete.
Cinq sporting 1242cc
http://mysite.freeserve.com/close_to_cracking_up/