Which speedo geer do i get?

I just read the thread about the Superlift true speed device. Someone suggested just getting a new gear. Which is what i had planed on doing. I know that the stealership can get them but would they know what tooth count to give me, and if not is there a chart somewhere that could get me close. I'm curently running 31's and its not off very far 3-mpi at 60 so it isn't bothering me yet. I'm planning on 32's next set of tires, and a gear change if i have the money.

Gojeep has a chart on his site, there's another one at http://www.ilovejeeps.com/forums/showthread.php?s=&postid=91995#post91995

Thanks Yucca-man that was the direction pointer i was looking for

Here my site kindly refered to above my friend

www.go.jeep-xj.info

Has pictures to show how easy it is to do as well.