>>>How can I tell if the input shaft is very slightly bent?  Wouldn't there be
>
>>With the engine out, jack up one wheel and turn that wheel.  The trans shaft 
>>will turn,  anrd will wobble if bent.
>
>Obviously! But what if is just very slightly bent?  I did turn the wheel,
>and I didn't notice any pronounced wobble.  Such a wobble would make the
>car almost undriveable, right?  But a VERY SLIGHT bend might go unnoticed,
>and would create stresses that cause mechanisms like a clutch to fail
>prematurely.

Sorry, sure it's obivous.  If you can't see it when ya look at it real hard, 
I don't think it's your problem.  But the next step would to put a dial 
indicator on it and watch.  
That's probabally obvious too.
  Chris Bridge
  
  Currently building an engine for a ''71 Westy (Sportsmobile?)
  E-mail cbridge@vt.edu