Normally, on a conventional clutch setup, the throw out bearing floats in a fork, and when you press on the clutch pedal, it push against the splines of the pressure plate and releases the clutch.
On the tib, the throw out is suspended on 2 fork rods, and is snapped in to the splines, so in all aspects, is part of the pressure plate, so when you press on the pedal, it pulls the splines to release the clutch -
So, if you do not understand how it works, and think it works like a conventional clutch, you press on the clutch to release the clutch, but in reality, you are pulling the throw out away from the clutch.. and your clutch doesn't work... many a tranny has come back out because people did not understand how it worked.. because for decades, they functioned the other way.
So, put the throw out on the fork, put it back together - and then turn the actuator rod over and push instead of pull, and the throw out snaps in to place and becomes part of the pressure plate.. it now works. Also, for those going with a stage 3 or better clutch on a lightened flywheel, be prepared for it not to shift properly... And sometimes, it will not even go in to gear while the engine is running - this is only temporary, start the car with it in gear and the clutch pressed in and drive it around for a few miles shifting as much as possible in the lower gears.. that will loosen it all up