Mini tub tire size question
I run a 28x12.50 (13.1 section width on a 11.25" wheel and they are tight, really they are too tight.
The 31 may be a issue too. My axle is moved back 1.5" and
I don't know if a 31 will fly. Plus to get ride height you'll have a ton of tire I the well and it narrows as it goes up.