tires

i have a rubicon 3.5 inch lift that i got about 4 inches out of and it is almost time for new tires. I would like to go bigger than 31x10.5, but i am not ready to trim yet. what would be the biggest i could go? I was thinking 32x11.5. how much backspacing would i need? i tried searching but couldn't find exactly what i was looking for. also has anyone used these tires https://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Road+Venture+MT+KL71&vehicleSearch=false&partnum=215QR5KL71&fromCompare1=yes&place=4
they are pretty reasonably priced. give me your opinions. Thanks

with 4 in. i think 31x10.50 is about max with out trimming but go to a tire shop and see if they will let you try a 32 before you buy them
the discount tire in my area let me try some tires to make sure they will fit before i bought them.

jusin