Hy krazymatt, what engine are you working with, the parts book shows a shorter throwout bearing for a 327 engine o.e.m. p/n 900018 (1 1/4" long). There are two different designs of diaphragm clutches, a flat finger design that would probably use the longer throwout bearing, and a bent finger design that would use the shorter throwout bearing, this design probably places the clutch fingers very close to where the fingers would be on the coil spring (Borg & Beck) pressure plates mentioned by LGriffin above. The Napa p/n BRG N3068SA is the crossover from 900018, hope that helps.
