If I remember correctly two holes are OK with 10mm, and the two in the rear are kind of short. It might be OK but I wouldn't do it myself (wouldn't want to pull the threads out of the carb body). If you have to cut down longer screws to match the stockers.
P.S. I bought 10mm first myself, but decided not to use them :cry
Replace those crappy screws as fast as you can. $7000 for a quad and they put the cheapest screws in it they could find. Tip:Use the P2 size Phillips head scredriver, put it in the screw and give the end of the screwdriver a good tap with your hammer. This will seat the screwdriver into the screw and you should not have any trouble with stripping. Then take those POS screws to the dealer and get him to give you some made from a harder metal. That's what I did and I could not have been happier.