I think I found one posting on the subject, so I've rebuilt a 54 235 and 4speed. Tranny has new bearings, seals and synchros. Just recently started up the engine after several years of body restoration. With engine not running you can turn the output shaft by hand and of course in gear you cannot. I read on another site that with fluid movement in neutral the tranny becomes a fluid drive and turns the output shaft. Has there been others with the same issue. The drive shaft is not connected at this time.