64 valiant 4 speed conversion questions.

You will need the early bolt on pivot for the early z bar.
You may find clearance issues with the big sb later yr/style bell housing. I remember when I was messing with them it was something lame ..like I had to use a small clutch/flywheel or 10in truck style from a slant...and early bellhousing for the early car to get by without cutting the transmission hump at the firewall for clearance and adding and 1" or so...but I'm not certain since it's been a minute.