i want to bag my box with 20's but i dont want to do a lot of body work. if that dont work then what size rim will

 

I am pretty confident that if you put 20's on your box, you will have to roll the fenders.

 

What we really need is a little more detail.

The simple answer is yes, you can bag your xB with 20s. To qualify that answer though... You will need proper wheel fitment, and you will not lay all the way out. Even with the best fitment your wheel wells will rest on your tires. With bad fitment it could mean quite a bit of "massaging" to make it work.

If you want to lay all the way down on 20s, it will take some pretty extensive fabrication. A custom air suspension would have to be built as well as lots of clearance work for your wheels and tires.