What size tire width can I fit with no backspacers

Hello everyone. I have 31"x10.5 tires on now which rub a little bit at full lock. Tomm. I'm getting 31"x11.5 tires. Will these tires be ok with no backspacing? I don't mind a little rub at full lock. Just wondering what the max width for a 1990 cherokee is with stock rims. I also have a 4.5" lift if that matters.
Thanks

With 31x10.5 the fronts were fine with my 3.5 lift, but the rears rubbed my leaf springs(OME HD) at static ride height and stock BS wheels. I went to 1" spacers and I hate them. I just ordered 5 new 15x7 Crager soft 8's.