I had the same thing happen when I replaced the clutch on my car. slave rod kept coming out the end of the slave cylinder. after some reading on here, i came to the same conclusion you did about the throw out bearing length. my fix was to cut the slave rod at an angle and weld it back together, slightly rotated to lengthen the rod. I haven't had any problems with it since. there was some suggestion of an adjustable slave cylinder like what is on the 240z, but for the 280z, (do some searching on here, Thread is not that old) but i did not look into it much, as i had already fixed mine in the wa