The largest stock
tire for your Jeep is the 245/70R15.
This came from the factory on 96 Laredo's with the Up Country suspension.
Here's something to think about
the OEM 225/75 tire=
tread width - 168.75mm
sidewall - 56.25mm
the aftermarket 235/75 you have now=
tread width - 176.25mm
sidewall - 58.75mm
the optional OEM 245/70 tire=
tread width - 171.5mm
sidewall - 73.5mm
So, if you want to fill the wheelwell, the 245 looks like the way to go, but if you want more tread width, the 235's you are accustomed to appear to be the ticket. Not to mention the shorter sidewall will induce less body roll in turns.