Hello Gang; It is my understanding that the extended bell housings were used from the 1951 model year until late in the1953 production year. It seems to me that this would correspond with the demise of the M6 semi-automatic and the introduction of the Powerflyte transmissions. Every source that I have run across would indicate that this is the case. It would seem to me that if it were otherwise then you would run across Powerflytes without a bell housing. The M6 transmissions were also used on flathead six's which did not have that extention on the back of the block so obviously they were built with a bell housing as well as without, but I think that it was detachable. I do know that the late production 1953 Imperials did come with the Powerflyte so a change in engine blocks would only make sense around the same time. If I had a car with the Fluid Torque Drive or M6 transmission I would probably keep it. From what I understand from people that have owned them, they were a very reliable device. Another reason that I would keep one is that the M6 is fairly unique in that it is an automatic with a clutch pedal and, as such, has many of the advantages of a standard as well. Best Regards Arran Foster 1954 Imperial Newport Needing A Left Side Taillight Bezel and other trim parts. ----- Original Message ----- From: <mopar48291@xxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Friday, February 22, 2002 8:10 PM Subject: IML: 53 Fluid-Torque switch to Powerflite > I believe that '53 has a one year only bell housing for > the Powerflite that allows it to be mated to the same > engine as the Fluid-Torque trans. '54 has the newer > style bell housing that is PF only. I've driven '53s > with both trans, and I think the Fluid-Torque is quicker > than the Powerflite, even left in high range. > > My '54 is slow off the line, but her rear end is a 2.93 > instead of the original 3.54, so she's built for > cruising, not street racing. > > Cheers, > Roger > >