Oh, yeah your right. LOL!
I ran 32's with just a 1" body and 1" shackle and flares trimmed and mine rubbed at hard full flex off road but were ok on the street. I then raised the flares so they might have cleared then but I did the 2.5" springs at the same time so....
Also I have no bump stops so if you had the 1" bl and 1" shackle with some opened up flares and maybe a small bumstop extension you MIGHT be ok with 32's but 31's would fit for sure.
IIRC i had 30's on mine with stock everything with trimmed fender flares and saggy springs and had no issues so 31's might go on with just the shackle lift and some fender flare work. 31's are only a 1/2 taller.
Also my 32's are not on stock rims so they have an 3.75" offset vs the ?5.5"? stockoffset. I also had to add to my steering stops so the tires would not rub the springs.
Lotsa different ways to do things.