<VV> Clutch assembly or transaxle?

[Sms116 at aol.com]

This if my first attempt at a posting, so be patient with me!  I have a 65 
Corsa that has a professionally rebuilt 140 in it. When started, and put in 
gear, it periodicaly makes a horrible grinding sound. I pulled the powertrain and 
removed the transaxle expecting to find some kind of evidence (metal shavings) 
but cant find anything. The engine runs great in nuetral...this noise is only 
when put in gear. The transaxle was fine when removed for the engine rebuild, 
so i was guessing something in the clutch assembly. Can anyone help??