Replacing broken or burnt out sealbeams (with poor output) in my 2002 TJ was becoming tiresome, so I had a look at the new '07 JK headlamps. The new Jeep lamps look way tougher, with plastic lenses and have replaceable(and upgradable bulbs). They looked like the same diameter, but mounting was a mystery. Mystery solved.
2007 JK lamps are a direct replacement to the sealbeam variety. The mounting(aiming) rings on the TJ accepted the new housings perfectly. The locator tabs are right on the money. The one main difference is the wiring connection. The old connector for the sealbeam has to be replaced with one that accepts a H13 bulb. Plus you have to recycle your old steel trim ring as they have moved the mounting tabs slightly. You can use the supplied mounting ring to utilise all new parts if you wish.
Cost is a bit of an issue, the LH and RH headlamp housings are about $155.00 each plus the cost of the wiring connectors. I have ordered a headlamp wiring harness for a '07 Chevrolet HHR, it is cheap($50.00)and includes 2 H13 connectors( I have not received it yet so this is unconfirmed as yet). I'll try to post pics as the project parts arrive and I install the parts. I only ordered one lamp for testing purposes.