Check the fins between the tubes. All the jeep 4.0 radiators that I have had go bad where the cooling fins separate from the tubes. I always replace with a 2 row, it may be more than needed but I figure the thermostat can control the flow and maintain the temp. A single row may work fine depending on your area, ambient temp, driving habits, and traffic patterns.
I also get the all metal radiators and stay away from those with plastic end caps.