273 and push button

Hey how’s it going!

My 64 currently has a slant 6 with a push button 904 transmission. I have a lead on a 69 273 V8 with 904 transmission.

Questions
Will the 273 bolt right up to my current 1964 904 Transmission? Can I use the 1969 transmission with push button mechanism? Any advantage in using the 1969 904?

Any info I would appreciate it.