I'm assuming that the shop would balance the parts separately, right? If not, then if/when you replaced a part (clutch for instance) then the 'whole' assembly could be unbalanced again. This could happen even if you balanced the new part before installation.

Rance

66 C10 FS/LB 292/4-spd manual (I also enjoy Hang Gliding)
I'm too sexy for my hair, that's why it isn't there