I can tell you that if you don't want to trim, I'd keep the overall diameter to about 30". I have a 2" BB and 30.5s (265/60/18) and they rub a bit on the front. It's fine for light trail use and daily driving, but when I get replacements I'm going back down to 30".
2004 Imola BMW ZHP
2006 Commander Limited Hemi QD2
"Bought, Not Built"