transmission compatibility for 1956 Cadillac

[Pat Rizzo]

I would like to upgrade the trans on my '56 coupe de ville. Can anyone tell me the best way to do this and what type of trans will I need to make the change. I also would like to upgrade the master cylinder. I should explain further that I do not want another 50's Cadillac transmission but a more modern one, say from the sixties or seventies or even newer. I'm assuming of course  that I will need a adapter plate. I am not worried about originality as the Jet-away trans was certainly not one of Cadillac's best. So rebuilding is out of the question. 

[dplotkin]

Your question comes up quite a bit-you can search this forum to find what has been said about it.

I do not believe a Turbo 400 or 700 will bolt up without an adapter and a lot of other machinations. The transmission that belongs there, if rebuilt & updated properly (many of us have done this) is efficient and reliable.

Why do you want to upgrade? What do you seek to accomplish?

Dan

[TJ Hopland]

Were you unable to answer the question from the info given in the other thread you started asking the same question?   Having more details in the subject this time will help more people see it this time but several people with experience in that era saw it last time and replied.

http://forums.cadillaclasalleclub.org/index.php?topic=136364.0

I know I and a few others kinda derailed the thread a bit asking and learning about differences in the designs and theories but before we did that I thought that some people with experience with this era car gave some good answers as to the complexity and downsides to a swap and gave some details about the changes / improvements in that series trans that could be done to an early model to make them more reliable. 

As for the brake question that too comes up often.   Does a 56 have a Treadle Vac or Hydra Vac?  Once you figure that out and search you will likely turn up several threads with various options but much like the trans question there is no simple bolt on 'upgrade'.  Sure there are things that can and have been done but it really depends on your goals, budget, and resources. 

[Dan LeBlanc]

The first question that comes to mind is upgrade it to what?  A newer dual range Hydramatic or something totally different?

[dplotkin]

Well, yes. There was no newer dual range Hydra-Matic after 56, which was the first year for the all new controlled coupling Hydra-Matic. It lasted through 64 and was improved for reliability along the way but it was always the same transmission that behaved the same way. Once at speed they are efficient, the fluid coupling providing better efficiency than a torque converter equipped transmission.
For hobby use, the re-engineering needed to install a late model transmission seems hardly worth the trouble. If you said you were to make a daily driver out of it and commute on interstates each day I would tell you to use the money on a used Camry and leave your Cadillac alone.

Dan