No lift?

They will rub when you turn.

yea hes right if your rig is unlifted theyll rub
i have a comanche, with that i cut the fenders and can run 31s, not sure how a grand cherokee would look with them cut though lol

They should fit

Yeah, it's a stock suspension rig.  I've heard others claim that they fit w/ little to no rubbing.  If it's only going to make contact at full steering lock I'm not really worried.  

You will if at near full lock you hit a bump and puncture a tire.

...ok, point taken.  Guess I'll stick with the 235/75R15's that are on it currently.
Thanks to everyone who took the time to respond to my question.  

You can do a cheap budget lift to accommodate larger tires very easily.  A 2 inch spacer will "lift" the springs a couple inches.  Ride quality won't change much if at all.  I can't remember if the ZJ has rear leaf springs or rear coils though.

These lifts only cost a few hundred bucks if that.  If you really plan on doing some off-roading, longer shocks are a must.

I've got 245/75/16 MT/Rs on my Cherokee. I mounted them on a set of Ford Ranger rims. The offset was enough to keep anything from rubbing. I've gone everywhere with it including some nice off-roading and tons of regular driving. Never had a blowout or anything like that.

I did have a problem with the tires scrubbing the inner, rear fender when I hit a large bump, but the leafs are shot. All I did was put a two inch block kit in the back and it fixed the problem. A one inch block kit probably would have done the trick too. Besides that, everything is stock.

All you have to do is get one mounted at a local shop and try it on the front and turn it from lock to lock to see if it scrubs anything. They should have no problem doing this. We do this all the time at my shop.

If you go with the Ranger rims (they look almost like Rubicon rims) you just have to shave down the little lip on the inside of the center so they sit on the hub correctly. You can also look for a set of Rubicon rims at a salvage yard or on ebay.

If you're looking for a cheap lift, Rusty's Offroad is the way to go. They sell a three inch lift complete with everything for $400 compared to Skyjacker's $800 and it's the same stuff.

You can also buy your spacers for under $15 each at carquest.

well i have a 2000 grand and i put 255/65/16 on my jeep. i'm not sure about the zj models. but if you go to your tire shop they should be able to tell you and if the 70 scrub you should just go to a 245/65 and the scrub should go away.