Most of the aftermarket wheels are 12x7 thats what I run. Most people run 10" wide on the front and 12" wide on the rear. So you need 4 wheels 12x7 and your tires should be 27x10x12 front 27x12x12 rear or you could run 27x10x12 front and rear that will help with weight and you won't lose as much power. I run 28x10x12 all the way around.

 

Mud National guys are going through thick mud, the water won't clog a radiator. It will actually clean it AND help cool the entire system. The whole engine is submerged. Very good cooling going on!

 

ITP 589's come in 27x9fronts and 27x11 rear-they will work fine on 12x7 rims with no clearance problems, i have them on my 500HO and they will stand up fine in the water when it gets too deep, the first time it happens it will amaze you that the front end stands up so easily. you should be careful not to go over backwards-most of the guys on the vids. have big boxes on front racks to help balance the quad. You can run a sportsman without snorkels pretty deep, but if you mess up and get off balance the snorkels can save your quads engine/clutch.