T56 magnum install 69 Cuda

Hey folks. We got the floor all buttoned up and things are going great. I'll get some pictures uploaded this afternoon. I Want a little bit of information.
All my cars are small blocks.
Other than the bellhousing bolt patern, are most of the other dimensions for the big block transmissions the same as the small blocks?? I know there are short and long tail shafts, but I believe that is due to the different body sizes (a,b,e).
SO... Are all 67 and up A-bodies transmissions the same, ie the mount location etc. I am just wanting to ensure that my parts will work with small and big block cars. Thank you for any help on this!! Todd