I just finished the swap in my YJ. I love it. I was born and raised in Morgantown PA, but living in VA right now. Jeff Daniels is good shop, but they are super expensive, I asked them to quote me to do the swap just for kicks, and they quoted me at around $22,000!
I think the swap is great for long expeditions, the diesel just chugs along. I think it is great on the trails because you have low RPM torque that gets ya over everything.
If you gear it right, its great on the highway too because thats when you build plenty of boost to pass anyone.
Check out my build thread.
4BT Cummins Swap Build Thread, PICS! - JeepForum.com