also, keep in mind on z32 clutches, there is 2 spots to bleed the air out of the lines and if you dont use both, you wont get all the air out. 1 of the spots is the slave cylinder. The other spot is under the hood of the car on the passenger side inner fender. Its a metal line that comes up to a metal block of sorts that has a bleed valve on it.
NOTE: I have only ever seen this bleed port on TWIN TURBO Z's. Alot of guys take this bleed point line out to clean up the engine bay, but if yours is still there, you will want to bleed it, that will probably be your problem.... hope that helps!