as long as you stay 1 size bigger in the front then the 4x4 will be fine..25"front and 24"rear should be fine..

 

i have 12" c-series type 4 rims and 25" tires all the way around my 2004 scrambler the differance is amazing i can now mud better than my buddies kodiak and ozark. i had to increase rear sprocket teeth to return gear ratio for 4x4 to work right and this also gave me better gearing for the oversized tires i put kenda bearclaws on it 25x8-12 on front and 25x12.5-12 on rear , with a epi bigfoot clutch, white bros. e-series exhaust, k&n air filter, dyno jet kit, and epi bigfoot brake pads. you will loose some of the sporty feel and becomes more unstable at high speeds but the trade off with all the traction and increased ground clearance is worth it. the pipe and clutch kit made my scrambler feel like it is on steroids i no longer need to slam my but way back to wheelie i can pull myself as far forward on the gas tank (i weigh 230lb) as i can and it still wheelies like right now . i did alot of research to get this set up correct most of it here pm me if you want to know how to figure out what size sprocket you will need to make the 4x4 ratio correct it is simple geometry. i will be posting some pictures with in a few days so you can check it out.



oh yeah 25" will be all the bigger you can go in the rear because the lugs will rub the floorboards

 

check out mngoat's gallery,he has 29.5 inch tires on his scrambler 500.looks pretty bada$$

 

I have a 99 Scrambler 500 with about 4,000 miles on it that is ready for a new set of tires. Since I don't like mudding but I do a lot of log-hopping in the mountains, I could use the higher clearance. Looking forward to seeing your pics and maybe I will try that route.

 

wow! mngoat's pics are awsome hope to get those pics from my friends camera soon and post