How big can i go?

I have a 1989 GMC jimmy 4.3 4X4 stock. My question is how big can i go on the tires before they rub really bad. My stock size tires are bad and i have a set of 32-12.50-15 sittin in my garage. this is not adaily driver mostly a fun truck for hunting and stuff sometimes drivin around town and town the highway.

on my 99 jimmy i am running 31x10.5 and they rub slightly when you turn but i dont think i could fit another size under without a ton of fender trimming. i dont think you can fit the 32s without a body lift and i dont think i would try it. this is what 31s do to my fenders when you hit a bump and even though it isnt an every day driver hearing your tires hit your wheel well makes you cringe alittle.
http://img.photobucket.com/albums/v386/thad/tires5.jpg

What if i turned the torsion bars up and put add a leafs inthe back, you think they would fit then. just a little tight on $ right know and i already have these and i can get some add aleafs for bout 30$. I dont know, would it be worth the try. Dont really want to use my $32,000 avalanche to go off road with:nono:.I only paid 800 for the truck so im not really worried bout the fenders

I was actually thinking about doing the same thing to my truck. I think you can actually get away with it. I will show you a picture of my tires sitting in the fenders and you can make the judgement yourself.

Rear:
http://img.photobucket.com/albums/v386/thad/tires1.jpg

Side:
http://img.photobucket.com/albums/v386/thad/tires4.jpg

It looks like you may have enough room. Let me know how it goes.

Ok thanks im thinkin about doing this in the next day or so so il let ya know how it works out.

i was thinkin bout puttin some bigger tires on to after the ones tat r on there get worn down
those 31s look nice
how much were they
i am lookin to get some fairly cheap but decent a/t tires in the next few months

They are Definity Dakota M/T they cost $100 a tire from PepBoys. They had a special buy 3 get 1 free with rebate I dont know if it is still running. I think the Definity tread is the same as a Cooper tread but im not sure.