You do not want to do this , You will be replacing the differental if you do.The rim sizes have to match.Like Buster said in 2wd you would be alright but in 4wd your front diff.would be spinning quicker than your rear diff.
I have the 26-10-12s on the front of mine and it steers just fine. What is your reason for not wanting the 10s? I used my stock rims. I didn't notice a lot of difference in the way it steered. It will not handle like stock, however.