whats the best size (wide) wheel to put on 31x10.50s?
i want it to stick out a little. would a 10incher be to wide?

 

I have 31x10.50's on a 10 inch wheel. Seems to work just fine.

 

i used an 8inch wide wheel with those size tires, any bigger and the sidewalls might balloon out a little.

 

Every tire size has an approved rim width range. 7" to 9" is the approved rim width range for that size tire. The rim width range is there to let people know what the safest range in rim width is to ensure that the internal stresses on the tires remain within their design range. Will that size mount to a 10" rim? YES... but it puts you outside the approved range.

Some vehicle manufacturers and tire companies have permitted rim widths that are not within the tire's original approved rim width range, but I've never seen any approvals for any more than 0.5" outside the approved range (either larger or smaller).

It's the same as driving 120MPH on a tire rated for 90MPH. Will it work? Sure, but how long do you want to test your luck?

If you just want the tires to stick out more, get wider tires to go with your wider wheels, or get different backspaced wheels.

 

if you want them to stick out a bit more why not go for a rim with less backspacing?