Are there any differences between the 1954 and 55' Hydramtic transmission,
or are they exactly the same?

 

I am pretty sure the 54 and 55 are the sam but I know the 56 is different. Sorry I am not 100%.

 

Burnout-dave, 54 55 and early 56 are the same. Mid 56 Olds changed,they added a park feature and and transmission cooler outlets.Both will bolt up the same and are good transmissions. Some say the 54 55 is a bit stronger if you are going to build a HP motor...Tedd

 

Thank you very much.....