I think replacing the dash is too much work.
Doors, not such a problem.
Do you need the doors to match the dash?
I'm pretty sure that cutting the 66 dash and adding the bracket for the shifter is easier than cutting out the entire dash (spot welded), then welding in the 68.
Adding the 4 way flasher is easy, just one hole to drill (I added that in my 66).

Ran


"Hey mister, something's wrong with your car, it idles roughly" - number one comment I got in Israel when daily driving a 70 Barracuda with a lopey cam.

Currently working on - 1966 Dodge A100 van 318/auto
Finally - disc brakes on the front.
In the plans - rear disc brakes, B&M 250 blower