I have tried a couple of different versions of the hydraulic throwout bearing setup (where the slave fits around the input shaft and you use shims to set the spacing). I have never successfully gotten one of these to work. As soon as you put any power to the clutch via burnout or qtr-mile shifting, the heat in the clutch would boil the clutch fluid and there went your clutch pedal. I tried all types of fluid (including the expensive 573 degree stuff) and drilling illegal vent holes in my bellhousing, but never got it to work for anything but commuting type driving. Go with the external slave unless there is no other option at which point I would strongly consider an automatic. I pulled the trans 6 times in 10 days during power tour 2000 to replace the orings in the slave. And I tried buna and viton o-rings as well.
