So I put a 2000 5.9 from a Durango in a 65 coronet.
For the throttle, I modified the 5.9 cable so it would work with the original gas pedal.
So I didn't change the mounting on the motor at all.
I kept my 727 and used an aftermarket system to control the efi.
The van setup is a little different, but nice because it tucks the power dr steering pump closer to the engine. Otherwise it sits under the battery tray.