Captain Obvious here. A console won't fit unless you have bucket seats.
Mopar put full length (Under dash to front seat backrest) consoles in the A-body beginning in 1966. As long as you get the brackets and linkage for the shifter you should be fine. IIRC, the 66 Dart GT buckets used the "Strato" seat which is a little narrower than the seats in the Barracuda. The 67 & later Barracuda used the "Strato" seat. Since the console was an option in both cars in 66, it would not appear to matter which seat you use.
You may want to check how the linkage attaches to the transmission of the donor car and be sure that you can do the same with yours. I've heard issues with people attempting to put pushbutton controls on newer transmissions with varying trials and tribulations. It may not be an issue in this case, but IMO it's best to know what's up ahead before arriving.