Overheating on the freeway.

Hi all, I posted this in OEM but perhaps you guys can help as well. When driving down the road at 60+ my 1995 seems to be getting hot (215-225+). This gets worse with A/C on (in 75 degree weather). When I slow down or am Idling, I stay at 205-212 with the aux fan varying on and off. Just had the radiator fixed 3 days ago (was cracked and leaking) but this problem started about 10 months ago - not an issue in the winter. I have overgeared to 4.56 (last fall) with 31's and I run in the 2500-3000 rpm range on the fwy. So, it is cool when slow but hot when at speed. Some have said the torque converter - mine does seem to have this issue - allowing slippage under power. Slippage = friction = heat. I have also heard of issues with the muffler but I have a flowmaster - 2.5 years old and I don't think it is bad. I have some vibe from the rear shaft but that shouldn't generate any heat. Any thoughts would be helpful - how do I fix it so that the jeep locks up my torque converter?

Thanks in advance,
Phil Hover

What about the fan clutch, blockage in the coolant systems, or maybe a backed up cat. converter.... I'm dealing with coolant system problems also. But not at fwy speeds only in the warm sun and in LA traffic.
Scott S.

Closing the thread.
You already posted it in OEM, no need to post it in two forums.