I don't have spacers on at the moment, but an extra 1/4 inch or so would help. As it is it works but its tight on the inside tub. These tires are Rawhide 3, 25x11.5x9, and they work well, Rawhide 25x12x9 would also work, as would the Argo 25" or 24" tires, or pretty much any similar sized tire.
Noel