Thought I would add my two cents. I built my 33 Plymouth with a cast iron TF behind the 392 (1957). I used the pushbutton assembly out of a 58 Dodge and it worked fine. However, ultimately, I was not happy with the CI TF and swapped in a TH350 out of my 40 Ford. I still have the pushbuttons to work it, although I would prefer to have PARK, which cannot be done with that mechanism. I went inside the tranny and reduced the detent spring force and built some pretty fancy linkage after the cable. I'm just about to switch to a B&M shifter, even though it won't be as cool.