The wheels will bolt on just fine.
The 265/75x16 has almost one more in of total OD @ 31.6 than 31x10.5x15 tires @ 30.8 OD.
Also, the 16" tire is not as wide as the 31x10.5x15.

I hope that helps... <img src="/forums/images/graemlins/cheers.gif" alt="" />