Ok guys...
I replaced my slave / throwout bearing about 2 months after I bought my 89 YJ. One day my foot went right to the floor...Bad deal. Luckly I was only few blocks from home. Anyway, I agree with getting the entire clutch/pressure plate/slave/throwout bearing kit. Since you are already have the tranny out do it all. As for what tranny you have check out http://www.jeeptech.com/convtrans/. There are pix of trannies. About a year later my ****** Peugeot BA 10/5 finally went so instead of rebuilding it or converting to the AX-15 I converted to the 904 3 speed auto with the slip yoke eliminator. Only $300 more for the auto conversion than an AX-15 conversion.

Oh by the way. If you decide to replace the slave yourself be sure to get a good set of Torx male and female sockets (impact type is preferred). There are 2 Torx head bolts on top of the bellhousing. After I removed all bolts I relized that I did not have Torx so next day got a set and finished. Now I have both male and female Torx.

Good Luck
4x4david