spigot is the bearing that sits in the end of the crankshaft that the input shaft of the gearbox runs in .In a t5 equiped commodore it is actually a bronze bush and it has no moving parts...the shaft just spins in it.The thust bearing is the throwout bearing which is totally different and it is a bearing and race assembly that pushes on the fingers of the pressure plate when you want the clutch to dissengauge to change gears etc by pushing on the clutch pedal.