has anyone done this? i believe the brackets are diff so maybe you can bolt the whole seat with brackets into a yj? just wondering if its worth it

A couple on J/U have done it.

http://forums.jeepsunlimited.com/ubb/Forum27/HTML/003045.html

I just did this about two months ago for a customer. All you need to do is take a few pieces of metal and make adapters to go from the YJ brackets to the TJ seats. Its really easy, and takes about and hour. All you need is so thick steel, drill, and a wrench. BTW the seats will sit up a couple of inches higher, so I you are short you will have a tough time reaching the pedals, but if you are tall, its actually easier to drive and is more comfortable.